CheckDigits.Net 3.0.0

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CheckDigits.Net

CheckDigits.Net brings together in one library an extensive collection of different check digit algorithms. CheckDigits.Net has the goal that each algorithm supported be optimized, be resilient to malformed input and that memory allocations be minimized or eliminated completely. Benchmarks for each algorithm are provided to demonstrate performance over a range of values and the memory allocation (if any).

Benchmarks have shown that the optimized versions of the algorithms in CheckDigits.Net are up to 10X-50X faster than those in popular Nuget packages.

Future Algorithms

Is there an algorithm that you would like to see included in CheckDigits.Net? Use the "Contact owners" link on https://www.nuget.org/packages/CheckDigits.Net and let us know. Or contribute to the CheckDigits.Net repository: https://github.com/KnowledgeForwardSolutions/CheckDigits.Net

Table of Contents

Check Digit Overview

Check digits are a useful tool for detecting data transcription errors. By embedding a check digit in a piece of information it is possible to detect common data entry errors early, often before performing more extensive and time consuming processing. A very common example of early error detection is validating a credit card number's check digit in the UI layer while the user is entering the credit card number before attempting to authorize a transaction with the card issuer.

Typical errors that can be detected by check digit algorithms include:

  • Single digit transcription errors (any single digit in a value being entered incorrectly).
  • Two digit transposition errors (two adjacent digits being swapped, i.e. ab → ba).
  • Twin errors (two identical digits being replaced by another pair, i.e. aa → bb).
  • Two digit jump transpositions (two digits separated by one position being swapped, i.e. abc → cba).
  • Jump twin errors (two identical digits separated by one position being replaced by another pair, i.e. aba → cbc).

Check digit algorithms attempt to balance detection capabilities with the cost in execution time and/or the complexity to implement. While check digits are designed to catch common errors early, they are not foolproof. Statistically, check digit algorithms are subject to "False Positive" results where the check digit appears to be valid, but the value contains a transcription error that the algorithm is not capable of detecting (for example, the Luhn algorithm fails to detect two digit transposition errors with the digits 9 and 0, i.e. 90 → 09 or vice versa). Conversely, check digit algorithms are not subject to "False Negative" results. If a value contains an incorrect check digit, then you can be certain that the value was not transcribed correctly.

ISO/IEC 7064 Algorithms

The ISO/IEC 7064 standard defines a family of algorithms capable of detecting a broad range of errors including all single character transcription errors as well as all or nearly all two character transposition errors, two character jump transposition errors, circular shift errors and double transcription errors (two separate single transcription errors in a single value). The algorithms are suitable for numeric strings, alphabetic strings, alphanumeric strings and can be extended to handle custom character domains beyond ASCII alphanumeric characters.

ISO/IEC 7064 algorithms fall into different categories. Pure system algorithms use a single modulus value and a radix value and can generate one or two check characters, depending on the algorithm. If a pure system algorithm generates a single check character, the check character produced will either be one of the valid input characters or a single supplementary character that is only valid as a check digit. Hybrid system algorithms use two modulus values, M and M+1, and generate a single check character that will be one of the valid input characters.

While CheckDigits.Net provides optimized implementations of all of the algorithms defined in the ISO/IEC 7064 standard, the standard is flexible enough to support the creation of algorithms for custom alphabets. For example, Annex B of the ISO/IEC 7064 standard demonstrates the creation of a system for the Danish alphabet which includes three additional characters.

CheckDigits.Net includes three classes to support custom alphabets:

  • Iso7064PureSystemSingleCharacterAlgorithm (generates a single check character, including a supplementary character)
  • Iso7064PureSystemDoubleCharacterAlgorithm (generates two check characters)
  • Iso7064HybridSystemAlgorithm (generates a single check character)

Refer to Using CheckDigits.Net for more information about using these classes.

The ISO/IEC 7064:2003 standard is available at https://www.iso.org/standard/31531.html

Supported Algorithms

Value/Identifier Types and Associated Algorithms

Value/Identifier Type Algorithm
ABA Routing Transit Number ABA RTN Algorithm
CA Social Insurance Number Luhn Algorithm
CAS Registry Number Modulus10_1 Algorithm
Credit card number Luhn Algorithm
CUSIP CUSIP Algorithm
EAN-8 Modulus10_13 Algorithm
EAN-13 Modulus10_13 Algorithm
FIGI FIGI Algorithm
Global Release Identifier ISO/IEC 7064 MOD 37-36 Algorithm
GTIN-8 Modulus10_13 Algorithm
GTIN-12 Modulus10_13 Algorithm
GTIN-13 Modulus10_13 Algorithm
GTIN-14 Modulus10_13 Algorithm
IBAN IBAN Algorithm
ICAO Machine Readable Travel Document Field ICAO 9303 Algorithm
ICAO Machine Readable Travel Documents Size TD1 ICAO 9303 Document Size TD1 Algorithm
ICAO Machine Readable Travel Documents Size TD2 ICAO 9303 Document Size TD2 Algorithm
ICAO Machine Readable Passports and Size TD3 Documents ICAO 9303 Document Size TD3 Algorithm
ICAO Machine Readable Visas ICAO 9303 Machine Readable Visa Algorithm
IMEI Luhn Algorithm
IMO Number Modulus10_2 Algorithm
ISAN ISAN Algorithm
ISBN-10 Modulus11 Algorithm
ISBN-13 Modulus10_13 Algorithm
ISBT Donation Identification Number ISO/IEC 7064 MOD 37-2 Algorithm
ISIN ISIN Algorithm
ISMN Modulus10_13 Algorithm
ISNI ISO/IEC 7064 MOD 11-2 Algorithm
ISSN Modulus11 Algorithm
Legal Entity Identifier Alphanumeric MOD 97-10 Algorithm
SEDOL SEDOL Algorithm
Shipping Container Number ISO 6346 Algorithm
SSCC Modulus10_13 Algorithm
Universal Loan Identifier Alphanumeric MOD 97-10 Algorithm
UK National Health Service Number NHS Algorithm
UPC-A Modulus10_13 Algorithm
UPC-E Modulus10_13 Algorithm
US National Provider Identifier NPI Algorithm
Vehicle Identification Number VIN Algorithm

Using CheckDigits.Net

Add a reference to CheckDigits.Net to your project.

Obtain an instance of the desired check digit algorithm. Either create an instance by using new AlgorithmXyz() or using the static Algorithms class to get a lazily instantiated singleton instance of the desired algorithm.

Calculate a check digit for a value by invoking the TryCalculateCheckDigit method.

Validate a value that contains a check digit by invoking the Validate method.

Examples:

using CheckDigits.Net;

// Create a new instance of the Luhn algorithm.
var algorithm = new LuhnAlgorithm();

// Get a lazily instantiated singleton instance of the Luhn algorithm.
var lazy = Algorithms.Luhn;


// Calculate the check digit for a value that does not already contain a check digit.
var newValue = "123456789012345";
var successful = algorithm.TryCalculateCheckDigit(newValue, out var checkDigit);  // Returns true; checkDigit will equal '2'

// Validate a value that contains a check digit.
var toValidate = "1234567890123452";
var isValid = lazy.Validate(toValidate);    // Returns true

Custom Alphabets for ISO 7064

The three classes that allow the use of custom alphabets are:

  • Iso7064PureSystemSingleCharacterAlgorithm (generates a single check character, including a supplementary character)
  • Iso7064PureSystemDoubleCharacterAlgorithm (generates two check characters)
  • Iso7064HybridSystemAlgorithm (generates a single check character)

To use one of these classes you must first create an instance of a class that implements IAlphabet or ISupplementalCharacterAlphabet. Then you create an instance of the desired generic ISO 7064 class, supplying the algorithm details (including the alphabet) to the class constructor.

The custom Danish alphabet check algorithm covered in Annex B of the ISO/IEC 7064 standard, uses a pure system algorithm that generates two check characters and has a modulus = 29 and radix = 2.

Danish Alphabet Example

public class DanishAlphabet : IAlphabet
{
   // Additional characters:
   // diphthong AE (\u00C6) has value 26
   // slashed O (\u00D8) has value 27
   // A with diaeresis (\u00C4) has value 28
   private const String _validCharacters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\u00C6\u00D8\u00C4";

   public Int32 CharacterToInteger(Char ch)
      => ch switch
      {
         var x when x >= 'A' && x <= 'Z' => x - 'A',
         '\u00C6' => 26,
         '\u00D8' => 27,
         '\u00C4' => 28,
         _ => -1
      };

   public Char IntegerToCheckCharacter(Int32 checkDigit) => _validCharacters[checkDigit];
}

var checkAlgorithm = new Iso7064PureSystemDoubleCharacterAlgorithm(
    "Danish", 
    "Danish, modulus = 29, radix = 2", 
    29, 
    2, 
    new DanishAlphabet());

// Calculate the check digit for Danish word for sister (uses slashed O instead of i)
var str = "S\u00D8STER";
var successful = checkAlgorithm.TryCalculateCheckDigits(str, out var firstChar, out var secondChar);    // Returns true, firstChar = 'D', secondChar = 'A'


// Validate a value containing check digit(s).
var isValid = checkAlgorithm.Validate("S\u00D8STERDA");     // Returns true

Interfaces

A check digit algorithm is a class that implements two different interfaces. Every algorithm implements ICheckDigitAlgorithm which has properties for getting the algorithm name and algorithm description and a Validate method that accepts a string and returns a boolean value that indicates if the string contains a valid check digit. Mal-formed input such as a null value, an empty string, a string of incorrect length or a string that contains characters that are not valid for the algorithm will return false instead of throwing an exception.

Check digit algorithms that use a single character also implement ISingleCheckDigitAlgorithm which has a TryCalculateCheckDigit method that accepts a string value and an out parameter which will contain the calculated check digit or '\0' if it was not possible to calculate the check digit. TryCalculateCheckDigit also returns a boolean value that indicates if the check digit was calculated or not. As with the Validate method, mal-formed input such as a null value, an empty string, a string of incorrect length or a string that contains characters that are not valid for the algorithm will return false instead of throwing an exception.

Check digit algorithms that use two character check digits also implement IDoubleCheckDigitAlgorithm. This interface has a TryCalculateCheckDigits method that has two output parameters, one for each check digit.

Note that ISingleCheckDigitAlgorithm and IDoubleCheckDigitAlgorithm are not implemented for algorithms for government issued identifiers (for example, UK NHS numbers and US NPI numbers) or values issued by a single authority (such as ABA Routing Transit Numbers).

The IAlphabet and ISupplementalCharacterAlphabet interfaces are used for ISO/IEC 7064 algorithms with custom alphabets. IAlphabet has two methods: CharacterToInteger, which maps a character in the value being processed to its integer equivalent and IntegerToCheckCharacter which maps a calculated check digit to its character equivalent. ISupplementalCharacterAlphabet extends IAlphabet by adding the CheckCharacterToInteger method which maps a check character to its integer equivalent. ISupplementalCharacterAlphabet is only used by Iso7064PureSystemSingleCharacterAlgorithm.

The ICheckDigitMask interface is used to define a mask that filters out characters from the value being checked. ICheckDigitMask defines IncludeCharacter and ExcludeCharacter methods that return true/false to indicate if a character at a particular zero based index should be included or excluded when calculating the check digit.

The IMaskedCheckDigitAlgorithm is derived from ICheckDigitAlgorithm and defines an overload for the Validate method that accepts an ICheckDigitMask instance that is used to filter characters from the value being checked. Currently only the Luhn Algorithm implements IMaskedCheckDigitAlgorithm.

ICheckDigitMask Example:


// Excludes every 5th character, allowing for spaces or dashes in credit card numbers.
public class CreditCardMask : ICheckDigitMask
{
   public Boolean ExcludeCharacter(Int32 index) => (index + 1) % 5 == 0;

   public Boolean IncludeCharacter(Int32 index) => (index + 1) % 5 != 0;
}

// Excludes the 4th and 8th characters from Canadian Social Insurance Numbers which breaks the SIN into groups of three digits.
public class CaSocialInsuranceNumberMask : ICheckDigitMask
{
   public Boolean ExcludeCharacter(Int32 index) => index == 3 || index == 7;

   public Boolean IncludeCharacter(Int32 index) => index != 3 && index != 7;
}

Algorithm Descriptions

ABA RTN Algorithm

Description

The American Bankers Association (ABA) Routing Transit Number (RTN) algorithm is a modulus 10 algorithm that uses weights 3, 7 and 1. The algorithm can detect all single digit transcription errors and most two digit transposition errors except those where the transposed digits differ by 5 (i.e. 1 ↔ 6, 2 ↔ 7, etc.).

The ABA RTN algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - ninth digit
  • Value length - 9 characters
  • Class name - AbaRtnAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/ABA_routing_transit_number#Check_digit

Alphanumeric MOD 97-10 Algorithm

Description

The Alphanumeric MOD 97-10 algorithm uses a variation of the ISO/IEC 7064 MOD 97-10 algorithm where alphabetic characters (A-Z) are mapped to integers (10-35) before calculating the check digit. The algorithm is case insensitive and lowercase letters are mapped to their uppercase equivalent before conversion to integers.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - two characters
  • Check digit value - decimal digits ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) characters when validating
  • Class name - AlphanumericMod97_10Algorithm
Common Applications
  • Legal Entity Identifier (LEI)
  • Universal Loan Identifier (ULI)

Wikipedia: https://en.wikipedia.org/wiki/Legal_Entity_Identifier

https://www.govinfo.gov/content/pkg/CFR-2016-title12-vol8/xml/CFR-2016-title12-vol8-part1003-appC.xml

CUSIP Algorithm

Description

The CUSIP (Committee on Uniform Security Identification Procedures) algorithm is used for nine character alphanumeric codes that identify North American financial securities. The algorithm has similarities with both the Luhn algorithm and the ISIN algorithm.

The CUSIP algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z') plus '*', '@' and '#'
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - CusipAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/CUSIP

Damm Algorithm

Description

The Damm algorithm was first described by H. Michael Damm in 2004. It is similar to the Verhoeff algorithm in that it can detect all single digit transcription errors and all two digit transposition errors and that it uses a precomputed table instead of modulus operations to calculate the check digit. Unlike the Verhoeff algorithm, the Damm algorithm uses a single quasigroup table of order 10 instead of the multiple tables used by Verhoeff. The implementation of the Damm algorithm provided by CheckDigits.Net uses the table generated from the quasigroup specified on page 111 of Damm's doctoral dissertation.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - DammAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/Damm_algorithm

FIGI Algorithm

Description

The FIGI (Financial Instrument Global Identifier) algorithm is used for 12 character values issued by Bloomberg L.P. that are used to identify a variety of financial instruments including common stock, futures, derivatives, bonds and more. The algorithm is a variation of the Luhn algorithm and has the same weaknesses as the Luhn algorithm with digit characters. But like the ISIN algorithm (which also extends the Luhn algorithm to support alphanumeric strings), the FIGI algorithm has additional weaknesses when detecting errors involving alphabetic characters. Each alphabetic character has a digit character and at least one other alphabetic character that can be freely substituted for that character and which will result in the same check digit being calculated. This means that single character transcription errors involving those characters can not be detected by the algorithm.

The FIGI algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9') and upper case consonants ('BCDFGHJKLMNPQRSTVWXYZ')
  • Check digit size - one character
  • Check digit value - decimal digits ('0' - '9')
  • Check digit location - character position 12 (1-based)
  • Value length - 12
  • Class name - FigiAlgorithm

https://en.wikipedia.org/wiki/Financial_Instrument_Global_Identifier https://www.openfigi.com/assets/content/figi-check-digit-2173341b2d.pdf

IBAN Algorithm

Description

The IBAN (International Bank Account Number) algorithm uses a variation of the ISO/IEC 7064 MOD 97-10 algorithm where alphabetic characters (A-Z) are mapped to integers (10-35) before calculating the check digit. Additionally, the first four characters (2 character country code and 2 decimal check digits) are moved to the end of the string before calculating the check digit.

Note that this implementation only confirms that the length of the value is sufficient to calculate the check digits (min length = 5) and that check digit characters in positions 3 & 4 are valid for the string. All other IBAN checks (the leading two characters indicating a valid country code, the check digit positions only contain digits, maximum length, country specific check digits contained in account number, etc.) are left to the application developer.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - two characters
  • Check digit value - decimal digits ('0' - '9')
  • Check digit location - character positions 3 & 4 (1-based) when validating
  • Value minimum length - 5
  • Class name - IbanAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/International_Bank_Account_Number

ICAO 9303 Algorithm

Description

The ICAO 9303 (International Civil Aviation Organization) algorithm is a modulus 10 algorithm used in the field of MRTODTs (Machine Readable Official Travel Documents). The algorithm uses weights 7, 3, and 1 with the weights applied starting from the left most character.

The algorithm can not detect single character transcription errors where the difference between the correct character and the incorrect character is 10, i.e. 0 → A, B->L, and vice versa. Nor can the algorithm detect two character transposition errors where the difference between the transposed characters is a multiple of 5, i.e. 27 ↔ 72, D8 ↔ 8D, BL ↔ LB).

Details
  • Valid characters - decimal digits ('0' - '9'), upper case letters ('A' - 'Z') and a filler character ('<').
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Icao9303Algorithm

https://en.wikipedia.org/wiki/Machine-readable_passport#Official_travel_documents https://www.icao.int/publications/Documents/9303_p3_cons_en.pdf

ICAO 9303 Document Size TD1 Algorithm

The ICAO 9303 (International Civil Aviation Organization) specification for Machine Readable Travel Documents Size TD1 uses multiple check digits in the machine readable zone of the document. The first line of the machine readable zone contains a field for the document number (including a possible extended document number) and associated check digit. The second line of the machine readable zone contains fields for date of birth, date of expiry and associated check digits for each field. The individual field check digits and the composite check digit are all calculated using theICAO 9303 Algorithm.

The machine readable zone of a Size TD1 document consists of three lines of 30 characters. The value passed to the Validate method should contain all lines of data concatenated together. You can specify how the lines are separated in the concatenated value by setting the LineSeparator property of the algorithm class. The three values are None (no line separator is used and the 31st character of the value is the first character of the second line), Crlf (the Windows line separator, i.e. a carriage return character followed by a line feed character - '\r\n') and Lf (the Unix line separator, i.e a line feed character - '\n').The default LineSeparator is None.

The ICAO 9303 Document Size TD1 Algorithm will validate the check digits of the three fields (document number, date of birth and date of expiry) as well as the composite check digit. If any of the check digits fail validation then the Validate method will return false.

The ICAO 9303 Document Size TD1 algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9'), upper case letters ('A' - 'Z') and a filler character ('<').
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - trailing (right-most) character of individual fields, trailing character of second line for composite check digit
  • Value length - three lines of 30 characters plus additional line separator characters as specified by the LineSeparator property
  • Class name - Icao9303SizeTD1Algorithm

https://www.icao.int/publications/Documents/9303_p5_cons_en.pdf

ICAO 9303 Document Size TD2 Algorithm

Description

The ICAO 9303 (International Civil Aviation Organization) specification for Machine Readable Travel Documents Size TD2 uses multiple check digits in the machine readable zone of the document. The second line of the machine readable zone contains fields for document number (including a possible extended document number), date of birth and date of expiry and associated check digits for each field. The individual field check digits and the composite check digit are all calculated using theICAO 9303 Algorithm.

The machine readable zone of a Size TD2 document consists of two lines of 36 characters. The value passed to the Validate method should contain all lines of data concatenated together. You can specify how the lines are separated in the concatenated value by setting the LineSeparator property of the algorithm class. The three values are None (no line separator is used and the 37th character of the value is the first character of the second line), Crlf (the Windows line separator, i.e. a carriage return character followed by a line feed character - '\r\n') and Lf (the Unix line separator, i.e a line feed character - '\n').The default LineSeparator is None.

The ICAO 9303 Document Size TD2 Algorithm will validate the check digits of the three fields (document number, date of birth and date of expiry) as well as the composite check digit. If any of the check digits fail validation then the Validate method will return false.

The ICAO 9303 Document Size TD2 algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9'), upper case letters ('A' - 'Z') and a filler character ('<').
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - trailing (right-most) character of individual fields, trailing character of second line for composite check digit
  • Value length - two lines of 36 characters plus additional line separator characters as specified by the LineSeparator property
  • Class name - Icao9303SizeTD2Algorithm

https://www.icao.int/publications/Documents/9303_p6_cons_en.pdf

ICAO 9303 Document Size TD3 Algorithm

Description

The ICAO 9303 (International Civil Aviation Organization) specification for Machine Readable Passports and other Size TD3 travel documents uses multiple check digits in the machine readable zone of the document. The second line of the machine readable zone contains fields for passport number, date of birth, date of expiry and an optional personal number field with each field having a check digit calculated using the ICAO 9303 Algorithm. In addition, the machine readable zone contains a final composite check digit calculated for all four of the above fields and their check digits. The composite check digit is also calculated using the ICAO 9303 Algorithm.

The machine readable zone of a Size TD3 document consists of two lines of 44 characters. The value passed to the Validate method should contain both lines of data concatenated together. You can specify how the lines are separated in the concatenated value by setting the LineSeparator property of the algorithm class. The three values are None (no line separator is used and the 45th character of the value is the first character of the second line), Crlf (the Windows line separator, i.e. a carriage return character followed by a line feed character - '\r\n') and Lf (the Unix line separator, i.e a line feed character - '\n').The default LineSeparator is None.

The ICAO 9303 Document Size TD3 Algorithm will validate the check digits of the four fields (passport number, date of birth, date of expiry and optional personal number) as well as the composite check digit. If any of the check digits fail validation then the Validate method will return false.

The ICAO 9303 Document Size TD3 algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9'), upper case letters ('A' - 'Z') and a filler character ('<').
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - trailing (right-most) character of individual fields, trailing character of entire string for composite check digit
  • Value length - two lines of 44 characters plus additional line separator characters as specified by the LineSeparator property
  • Class name - Icao9303SizeTD3Algorithm

https://www.icao.int/publications/Documents/9303_p4_cons_en.pdf

ICAO 9303 Machine Readable Visa Algorithm

Description

The ICAO 9303 (International Civil Aviation Organization) specification for Machine Readable Visas uses multiple check digits in the machine readable zone of the document. The second line of the machine readable zone contains fields for document number, date of birth and date of expiry and associated check digits for each field. (Unlike other ICAO 9303 TD1, TD2 or TD3 documents, no composite check digit is used.) The individual field check digits are all calculated using theICAO 9303 Algorithm.

Machine Readable Visas have two formats: MRV-A and MRV-B. The MRV-A format uses two lines of 44 characters while the MRV-B format uses two lines of 36 characters. The individual fields in the second line of the machine readable zone are located in the same character positions regardless of the format. The Validate method can validate either format

The machine readable zone of a Machine Readable Visa consists of two lines of 36 characters. The value passed to the Validate method should contain all lines of data concatenated together. You can specify how the lines are separated in the concatenated value by setting the LineSeparator property of the algorithm class. The three values are None (no line separator is used and the 37th character of the value is the first character of the second line), Crlf (the Windows line separator, i.e. a carriage return character followed by a line feed character - '\r\n') and Lf (the Unix line separator, i.e a line feed character - '\n').The default LineSeparator is None.

The ICAO 9303 Machine Readable Visa Algorithm will validate the check digits of the three fields (document number, date of birth and date of expiry). If any of the check digits fail validation then the Validate method will return false. In addition, if the value is not the correct length (two lines of either 44 or 36 characters, plus line separator characters matching the LineSeparator property) then the method will return false.

The ICAO 9303 Machine Readable Visa algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9'), upper case letters ('A' - 'Z') and a filler character ('<').
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - trailing (right-most) character of individual fields
  • Value length - two lines of either 44 characters (MRV-A) or 36 characters (MRV-B), plus additional line separator characters as specified by the LineSeparator property
  • Class name - Icao9303MachineReadableVisaAlgorithm

https://www.icao.int/publications/Documents/9303_p7_cons_en.pdf

ISAN Algorithm

Description

The ISAN (International Standard Audiovisual Number) algorithm uses a variation of the ISO/IEC 7064 MOD 37,36 algorithm and can have either one or two check characters. A full ISAN value consists of 12 hexadecimal digits for the "root" segment, 4 hexadecimal digits for the "episode" segment, an alphanumeric check character calculated for the 16 characters of the root/episode segments and optionally, 8 hexadecimal digits for the version segment and an alphanumeric check character calculated for the 24 characters of the root/episode/version segments. Per https://www.isan.org/docs/isan_check_digit_calculation_v2.0.pdf, both check characters must be correct if the value includes a version segment.

CheckDigits.Net can validate either unformatted ISAN values consisting only of hexadecimal digits and alphanumeric check characters or ISAN values that have been formatted for human readability.

To validate unformatted root+version ISAN values, use the Validate method. The Validate method only checks 26 character unformatted ISAN root+version values. (To check 17 character root/episode only ISAN values, use the ISO/IEC 7064 MOD 37,36 algorithm directly.)

To validate formatted ISAN values, either root/episode values or root/episode/version values, use the ValidateFormatted method. The ValidateFormatted method will check both the format of the value ("ISAN " prefix plus dash characters that separate the value into 4 character groups) and the check character(s) in the value.

An example formatted root/episode ISAN value is ISAN 0000-0000-C36D-002B-K. An example formatted root/episode/version ISAN value is ISAN 0000-0000-C36D-002B-K-0000-0000-E.

Details
  • Valid characters - hexadecimal characters ('0' - '9', 'A' - 'F')
  • Check digit size - one character
  • Check digit value - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit location - the 17th non-format character (and the 26th non-format character for root+version values)
  • Class name - IsanAlgorithm

https://en.wikipedia.org/wiki/International_Standard_Audiovisual_Number https://www.isan.org/docs/isan_check_digit_calculation_v2.0.pdf https://web.isan.org/public/en/search

ISIN Algorithm

Description

The ISIN (International Securities Identification Number) algorithm uses a variation of the Luhn algorithm and has all of the capabilities of the Luhn algorithm, including the ability to detect all single digit (or character) transcription errors and most two digit transposition errors except 09 → 90 and vice versa.

The algorithm has significant weaknesses. Transpositions of two letters cannot be detected. Additionally, transpositions of a digit character and the letters B, M or X cannot be detected (because B is converted to 11, M to 22 and X to 33 and when combined with another digit, the result is a jump transposition that the Luhn algorithm cannot detect).

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Value length - 12
  • Class name - IsinAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/International_Securities_Identification_Number

ISO 6346 Algorithm

The ISO 6346 algorithm is used for eleven character shipping container numbers.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Value length - 11
  • Class name - Iso6346Algorithm

Wikipedia: https://en.wikipedia.org/wiki/ISO_6346

ISO/IEC 7064 MOD 11,10 Algorithm

The ISO/IEC 7064 MOD 11,10 algorithm is a hybrid system algorithm (with M = 10 and M+1 = 11) that is suitable for use with numeric strings. It generates a single check character that is a decimal digit.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Iso7064Mod11_10Algorithm

ISO/IEC 7064 MOD 11-2 Algorithm

The ISO/IEC 7064 MOD 11-2 algorithm is a pure system algorithm (with modulus 11 and radix 2) that is suitable for use with numeric strings. It generates a single check character that is either a decimal digit or a supplementary 'X' character.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9') or an uppercase 'X'
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Iso7064Mod11_2Algorithm
Common Applications
  • International Standard Name Identifier (ISNI)

ISO/IEC 7064 MOD 1271-36 Algorithm

The ISO/IEC 7064 MOD 1271-36 algorithm is a pure system algorithm (with modulus 1271 and radix 36) that is suitable for use with alphanumeric strings. It generates two check alphanumeric characters.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - two characters
  • Check digit value - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit location - assumed to be the trailing (right-most) characters when validating
  • Class name - Iso7064Mod1271_36Algorithm

ISO/IEC 7064 MOD 27,26 Algorithm

The ISO/IEC 7064 MOD 27,26 algorithm is a hybrid system algorithm (with M = 26 and M+1 = 27) that is suitable for use with alphabetic strings. It generates a single check character that is an alphabetic character.

Details
  • Valid characters - alphabetic characters ('A' - 'Z')
  • Check digit size - one character
  • Check digit value - alphabetic characters ('A' - 'Z')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Iso7064Mod27_26Algorithm

ISO/IEC 7064 MOD 37-2 Algorithm

The ISO/IEC 7064 MOD 37-2 algorithm is a pure system algorithm (with modulus 37 and radix 2) that suitable for use with alphanumeric strings. It generates a single check character that is either an alphanumeric character or a supplementary '*' character.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9', 'A' - 'Z') or an asterisk '*'
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Iso7064Mod37_2Algorithm
Common Applications
  • International Society of Blood Transfusion (ISBT) Donation Identification Numbers

ISO/IEC 7064 MOD 37,36 Algorithm

The ISO/IEC 7064 MOD 37,36 algorithm is a hybrid system algorithm (with M = 36 and M+1 = 37) that is suitable for use with alphanumeric strings. It generates a single check character that is an alphanumeric character.

Details
  • Valid characters - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit size - one character
  • Check digit value - alphanumeric characters ('0' - '9', 'A' - 'Z')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Iso7064Mod37_36Algorithm
Common Applications
  • Global Release Identifier (GRid)

ISO/IEC 7064 MOD 661-26 Algorithm

The ISO/IEC 7064 MOD 661-26 algorithm is a pure system algorithm (with modulus 661 and radix 26) that is suitable for use with alphabetic strings. It generates two check alphabetic characters.

Details
  • Valid characters - alphabetic characters ('A' - 'Z')
  • Check digit size - two characters
  • Check digit value - alphabetic characters ('A' - 'Z')
  • Check digit location - assumed to be the trailing (right-most) characters when validating
  • Class name - Iso7064Mod661_26Algorithm

ISO/IEC 7064 MOD 97-10 Algorithm

The ISO/IEC 7064 MOD 97-10 algorithm is a pure system algorithm (with modulus 97 and radix 210) that is suitable for use with numeric strings. It generates a two numeric check digits.

Note: the ISO/IEC 7064 MOD 97-10 algorithm is the basis of a number of check digit algorithms that first map alphabetic characters to numbers between 10 and 35. Examples include International Bank Account Numbers (IBAN) and Universal Loan Identifiers (ULI). However this implementation is limited to values containing only decimal digits. Other algorithms will handle values like IBAN and ULI and perform the mapping of alphabetic characters internally.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - two characters
  • Check digit value - decimal digits ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) characters when validating
  • Class name - Iso7064Mod97_10Algorithm

Luhn Algorithm

Description

The Luhn algorithm is a modulus 10 algorithm that was developed in 1960 by Hans Peter Luhn. It can detect all single digit transcription errors and most two digit transposition errors except 09 → 90 and vice versa. It can also detect most twin errors (i.e. 11 ↔ 44) except 22 ↔ 55, 33 ↔ 66 and 44 ↔ 77.

LuhnAlgorithm implements IMaskedCheckDigitAlgorithm and can be used to validate values that are formatted with non-check digit characters (for example, a credit card number formatted with spaces or dashes).

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - LuhnAlgorithm
Common Applications
  • Credit card numbers
  • International Mobile Equipment Identity (IMEI) numbers
  • Canadian Social Insurance Number (SIN)

Wikipedia: https://en.wikipedia.org/wiki/Luhn_algorithm

Modulus10_1 Algorithm

The Modulus10 algorithm uses modulus 10 and each digit is weighted by its position in the value, starting with weight 1 for the right-most non-check digit character.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Max length - 9 characters when generating a check digit; 10 characters when validating
  • Class name - Modulus10_1Algorithm
Common Applications
  • Chemical Abstracts Service (CAS) Registry Number

Wikipedia: https://en.wikipedia.org/wiki/CAS_Registry_Number

Modulus10_2 Algorithm

The Modulus10 algorithm uses modulus 10 and each digit is weighted by its position in the value, starting with weight 2 for the right-most non-check digit character.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Max length - 9 characters when generating a check digit; 10 characters when validating
  • Class name - Modulus10_2Algorithm
Common Applications
  • International Maritime Organization (IMO) Number

Wikipedia: https://en.wikipedia.org/wiki/IMO_number

Modulus10_13 Algorithm

Description

The Modulus10_13 algorithm is a widely used modulus 10 algorithm that uses weights 1 and 3 (odd positions have weight 3, even positions have weight 1). It can detect all single digit transcription errors and ~80% of two digit transposition errors (except where the transposed digits have a difference of 5, i.e. 1 ↔ 6, 2 ↔ 7, etc.). The algorithm cannot detect two digit jump transpositions.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - Modulus10_13Algorithm
Common Applications
  • Global Trade Item Number (GTIN-8, GTIN-12, GTIN-13, GTIN-14)
  • International Article Number/European Article Number (EAN-8, EAN-13)
  • International Standard Book Number, starting January 1, 2007 (ISBN-13)
  • International Standard Music Number (ISMN)
  • Serial Shipping Container Code (SSCC)
  • Universal Product Code (UPC-A, UPC-E)

Wikipedia: https://en.wikipedia.org/wiki/Universal_Product_Code#Check_digit_calculation https://en.wikipedia.org/wiki/International_Article_Number#Calculation_of_checksum_digit

Modulus11 Algorithm

Description

The Modulus11 algorithm uses modulus 11 and each digit is weighted by its position in the value, starting from the right-most digit. Prior to the existence of the Verhoeff algorithm and the Damm algorithm it was popular because it was able to detect two digit transposition errors while using only a single character. However, because it used modulus 11, the check digit could not be a single decimal digit. Commonly an 'X' character was used when the modulus operation resulted in a value of 10. This meant that identifiers that used the Modulus11 algorithm could not be stored as numbers and instead must be strings.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9') or an uppercase 'X'
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Max length - 9 characters when generating a check digit; 10 characters when validating
  • Class name - Modulus11Algorithm
Common Applications
  • International Standard Book Number, prior to January 1, 2007 (ISBN-10)
  • International Standard Serial Number (ISSN)

Wikipedia: https://en.wikipedia.org/wiki/ISBN#ISBN-10_check_digits https://en.wikipedia.org/wiki/ISSN

NHS Algorithm

Description

UK National Health Service (NHS) identifiers use a variation of the Modulus 11 algorithm. However, instead of generating 11 possible values for the check digit, the NHS algorithm does not allow a remainder of 10 (the 'X' character used by the Modulus 11 algorithm). Any possible NHS number that would generate a remainder of 10 is not allowed and those numbers are not issued. This means that the check digit for a NHS number remains '0' - '9'. The NHS algorithm retains all error detecting capabilities of the Modulus 11 algorithm (detecting all single digit transcription errors and all two digit transposition errors).

The NHS algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Value length - 10 characters
  • Class name - NhsAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/NHS_number#Format,_number_ranges,_and_check_characters https://www.datadictionary.nhs.uk/attributes/nhs_number.html

NOID Check Digit Algorithm

Description

The NOID (Nice Opaque Identifier) Check Digit Algorithm is used by systems that deal with persistent identifiers (for example, ARK (Archival Resource Key) identifiers). The algorithm can detect single character transcription errors and two character transposition errors for values that are less than 29 characters in length. If the value is 29 character in length or greater then the algorithm is slightly less capable. The algorithm operates on lower case betanumeric characters (i.e. alphanumeric characters, minus vowels, including 'y', and the letter 'l'). The use of betanumeric characters reduces the likelihood that an identifier would equal a recognizable word or that the digits 0 or 1 could be confused for the letters 'o' or 'l'.

Details
  • Valid characters - betanumeric characters ('0123456789bcdfghjkmnpqrstvwxz')
  • Check digit size - one character
  • Check digit value - betanumeric characters ('0123456789bcdfghjkmnpqrstvwxz')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - NcdAlgorithm

https://metacpan.org/dist/Noid/view/noid#NOID-CHECK-DIGIT-ALGORITHM

NPI Algorithm

Description

US National Provider Identifiers (NPI) use the Luhn algorithm to calculate the check digit located in the trailing (right-most) position. However, before calculating, the value is prefixed with a constant "80840" and the check digit is calculated using the entire 15 digit string. The resulting check digit has all the capabilities of the base Luhn algorithm (detecting all single digit transcription errors and most two digit transposition errors except 09 → 90 and vice versa as well as most twin errors (i.e. 11 ↔ 44) except 22 ↔ 55, 33 ↔ 66 and 44 ↔ 77.

(You can create and validate NPI check digits using the standard Luhn algorithm by first prefixing your value with "80840". However, CheckDigits.Net's implementation of the NPI algorithm handles the prefix internally and without allocating an extra string.)

The NPI algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Value length - 10 characters
  • Class name - NpiAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/National_Provider_Identifier

SEDOL Algorithm

Description

The SEDOL (Stock Exchange Daily Official List) algorithm is used for seven character alphanumeric codes that identify financial securities in the United Kingdom and Ireland.

The SEDOL algorithm only supports validation of check digits and does not support calculation of check digits.

Details
  • Valid characters - alphanumeric characters, excluding vowels ('0' - '9', 'BCDFGHJKLMNPQRSTVWXYZ')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Value length - 7 characters
  • Class name - SedolAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/SEDOL

Verhoeff Algorithm

Description

The Verhoeff algorithm was the first algorithm using a single decimal check digit that was capable of detecting all single digit transcription errors and all two digit transposition errors. It was first described by Jacobus Verhoeff in 1969. Prior to Verhoeff it was believed that it was not possible to define an algorithm that used a single decimal check digit that could detect both all single digit transcription errors and all two digit transposition errors. Verhoeff's algorithm does not use modulus operations and instead uses a dihedral group (typically implemented as a set of lookup tables). Additionally, Verhoeff's algorithm can detect many, though not all, twin errors, two digit jump transpositions and jump twin errors.

Details
  • Valid characters - decimal digits ('0' - '9')
  • Check digit size - one character
  • Check digit value - decimal digit ('0' - '9')
  • Check digit location - assumed to be the trailing (right-most) character when validating
  • Class name - VerhoeffAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/Verhoeff_algorithm

VIN Algorithm

Description

The VIN (Vehicle Identification Number) algorithm is used on the VIN of vehicles sold in North America (US and Canada). The check digit is the 9th character of the 17 character value. Upper-case alphabetic characters (except 'I', 'O' and 'Q') are allowed in the value and must be transliterated to integer values before weighting, summing and calculating sum modulus 11.

Details
  • Valid characters - decimal digits ('0' - '9') and upper case letters ('A' - 'Z'), excluding 'I', 'O' and 'Q'
  • Check digit size - one character
  • Check digit value - either decimal digit ('0' - '9') or an uppercase 'X'
  • Check digit location - 9th character of 17
  • Length - 17 characters
  • Class name - VinAlgorithm

Wikipedia: https://en.wikipedia.org/wiki/Vehicle_identification_number#Check-digit_calculation

Benchmarks

The methodology for the general algorithms is to generate values for the benchmarks by taking substrings of lengths 3, 6, 9, etc. from the same randomly generated source string. For the TryCalculateCheckDigit or TryCalculateCheckDigits methods the substring is used as is. For the Validate method benchmarks the substring is appended with the check character or characters that make the test value valid for the algorithm being benchmarked.

For value specific algorithms, three separate values that are valid for the algorithm being benchmarked are used.

Previous .Net 8 benchmarks available at https://github.com/KnowledgeForwardSolutions/CheckDigits.Net/blob/main/Documentation/DotNet8Benchmarks.md

Detailed benchmark results for .Net 8 vs .Net 10 located at https://github.com/KnowledgeForwardSolutions/CheckDigits.Net/blob/main/Documentation/DotNet8_DotNet10_PerformanceComparision.md

Note that the benchmarks for version 2.x.x of CheckDigits.Net were run on an Intel i7-7700HQ CPU @ 2.80GHz computer while the benchmarks for version 3.x.x of CheckDigits.Net were run on an AMD RYZEN AI MAX+ 3950 CPU @ 3.00GHz computer. The comparison benchmarks between .Net 8.0 and .Net 10.0 were all run on the same newer computer to ensure accurate comparisons.

Benchmark Details

BenchmarkDotNet v0.15.8, Windows 11 (10.0.26200.7462/25H2/2025Update/HudsonValley2) AMD RYZEN AI MAX+ 395 w/ Radeon 8060S 3.00GHz, 1 CPU, 32 logical and 16 physical cores .NET SDK 10.0.101 [Host] : .NET 10.0.1 (10.0.1, 10.0.125.57005), X64 RyuJIT x86-64-v4 DefaultJob : .NET 10.0.1 (10.0.1, 10.0.125.57005), X64 RyuJIT x86-64-v4

TryCalculateCheckDigit/TryCalculateCheckDigits Methods

General Numeric Algorithms

Note that the Modulus10_1, Modulus10_2 and Modulus11 algorithms have a maximum length of 10 (including the check digit) for values being validated so their benchmarks do not cover lengths greater than 10.

Algorithm Name Value Mean Error StdDev Allocated
Damm 140 1.956 ns 0.0017 ns 0.0015 ns -
Damm 140662 3.367 ns 0.0102 ns 0.0096 ns -
Damm 140662538 5.075 ns 0.0045 ns 0.0040 ns -
Damm 140662538042 7.286 ns 0.0254 ns 0.0238 ns -
Damm 140662538042551 9.441 ns 0.0226 ns 0.0212 ns -
Damm 140662538042551028 13.189 ns 0.0125 ns 0.0105 ns -
Damm 140662538042551028265 16.549 ns 0.0689 ns 0.0611 ns -
ISO/IEC�706 MOD�11,10 140 2.256 ns 0.0292 ns 0.0273 ns -
ISO/IEC�706 MOD�11,10 140662 4.046 ns 0.0359 ns 0.0318 ns -
ISO/IEC�706 MOD�11,10 140662538 5.119 ns 0.0255 ns 0.0239 ns -
ISO/IEC�706 MOD�11,10 140662538042 6.555 ns 0.0703 ns 0.0657 ns -
ISO/IEC�706 MOD�11,10 140662538042551 8.083 ns 0.0997 ns 0.0933 ns -
ISO/IEC�706 MOD�11,10 140662538042551028 9.338 ns 0.0474 ns 0.0420 ns -
ISO/IEC�706 MOD�11,10 140662538042551028265 10.988 ns 0.0404 ns 0.0378 ns -
ISO/IEC�706�MOD 11-2 140 2.235 ns 0.0176 ns 0.0165 ns -
ISO/IEC�706�MOD 11-2 140662 3.839 ns 0.0250 ns 0.0234 ns -
ISO/IEC�706�MOD 11-2 140662538 4.636 ns 0.0240 ns 0.0200 ns -
ISO/IEC�706�MOD 11-2 140662538042 5.603 ns 0.0362 ns 0.0321 ns -
ISO/IEC�706�MOD 11-2 140662538042551 6.611 ns 0.0755 ns 0.0707 ns -
ISO/IEC�706�MOD 11-2 140662538042551028 7.308 ns 0.0351 ns 0.0329 ns -
ISO/IEC�706�MOD 11-2 140662538042551028265 8.910 ns 0.0669 ns 0.0626 ns -
ISO/IEC�706 MOD�97-10 140 2.926 ns 0.0236 ns 0.0221 ns -
ISO/IEC�706 MOD�97-10 140662 4.230 ns 0.0289 ns 0.0270 ns -
ISO/IEC�706 MOD�97-10 140662538 6.013 ns 0.0216 ns 0.0202 ns -
ISO/IEC�706 MOD�97-10 140662538042 7.501 ns 0.0379 ns 0.0336 ns -
ISO/IEC�706 MOD�97-10 140662538042551 9.122 ns 0.0407 ns 0.0361 ns -
ISO/IEC�706 MOD�97-10 140662538042551028 11.271 ns 0.0390 ns 0.0364 ns -
ISO/IEC�706 MOD�97-10 140662538042551028265 13.185 ns 0.0484 ns 0.0429 ns -
Luhn 140 2.739 ns 0.0284 ns 0.0265 ns -
Luhn 140662 4.375 ns 0.0256 ns 0.0227 ns -
Luhn 140662538 5.987 ns 0.0550 ns 0.0514 ns -
Luhn 140662538042 6.769 ns 0.0602 ns 0.0533 ns -
Luhn 140662538042551 8.452 ns 0.0505 ns 0.0448 ns -
Luhn 140662538042551028 9.905 ns 0.0575 ns 0.0538 ns -
Luhn 140662538042551028265 11.526 ns 0.0598 ns 0.0559 ns -
Modulus10_13 140 2.536 ns 0.0202 ns 0.0179 ns -
Modulus10_13 140662 4.280 ns 0.0267 ns 0.0250 ns -
Modulus10_13 140662538 5.105 ns 0.0284 ns 0.0265 ns -
Modulus10_13 140662538042 6.363 ns 0.0230 ns 0.0192 ns -
Modulus10_13 140662538042551 7.715 ns 0.0326 ns 0.0305 ns -
Modulus10_13 140662538042551028 9.209 ns 0.0357 ns 0.0334 ns -
Modulus10_13 140662538042551028265 10.628 ns 0.0633 ns 0.0561 ns -
Modulus10_1 140 1.808 ns 0.0124 ns 0.0096 ns -
Modulus10_1 140662 2.587 ns 0.0193 ns 0.0171 ns -
Modulus10_1 140662538 4.043 ns 0.0233 ns 0.0218 ns -
Modulus10_2 140 1.854 ns 0.0206 ns 0.0183 ns -
Modulus10_2 140662 2.656 ns 0.0145 ns 0.0136 ns -
Modulus10_2 140662538 4.024 ns 0.0173 ns 0.0162 ns -
Modulus11 140 2.364 ns 0.0171 ns 0.0152 ns -
Modulus11 140662 3.323 ns 0.0300 ns 0.0280 ns -
Modulus11 140662538 4.341 ns 0.0301 ns 0.0281 ns -
Verhoeff 140 4.250 ns 0.0312 ns 0.0277 ns -
Verhoeff 140662 6.399 ns 0.0542 ns 0.0452 ns -
Verhoeff 140662538 9.977 ns 0.0363 ns 0.0340 ns -
Verhoeff 140662538042 13.351 ns 0.0441 ns 0.0413 ns -
Verhoeff 140662538042551 16.793 ns 0.0614 ns 0.0574 ns -
Verhoeff 140662538042551028 19.818 ns 0.0811 ns 0.0758 ns -
Verhoeff 140662538042551028265 22.861 ns 0.0866 ns 0.0768 ns -
General Alphabetic Algorithms
Algorithm Name Value Mean Error StdDev Allocated
ISO/IEC 7064 MOD 27,26 EGR 2.178 ns 0.0032 ns 0.0030 ns -
ISO/IEC 7064 MOD 27,26 EGRNML 3.900 ns 0.0091 ns 0.0085 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOC 5.088 ns 0.0505 ns 0.0472 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECU 6.933 ns 0.0953 ns 0.0891 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIK 7.753 ns 0.0516 ns 0.0458 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIKNWW 9.899 ns 0.2137 ns 0.3570 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIKNWWVVO 11.228 ns 0.2467 ns 0.4694 ns -
ISO/IEC 7064 MOD 661-26 EGR 3.193 ns 0.0212 ns 0.0198 ns -
ISO/IEC 7064 MOD 661-26 EGRNML 4.940 ns 0.0303 ns 0.0268 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOC 6.459 ns 0.0187 ns 0.0174 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECU 8.844 ns 0.0380 ns 0.0297 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIK 11.127 ns 0.0432 ns 0.0361 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIKNWW 13.005 ns 0.0354 ns 0.0331 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIKNWWVVO 15.670 ns 0.0925 ns 0.0820 ns -
General Alphanumeric Algorithms

Note that the values used for the NOID Check Digit algorithm do not include lengths 3 or 6 so that benchmarks are not run on purely numeric strings.

Algorithm Name Value Mean Error StdDev Allocated
AlphanumericMod97_10 U7y 4.951 ns 0.0035 ns 0.0033 ns -
AlphanumericMod97_10 U7y8SX 8.103 ns 0.0134 ns 0.0112 ns -
AlphanumericMod97_10 U7y8SXrC0 11.861 ns 0.0131 ns 0.0116 ns -
AlphanumericMod97_10 U7y8SXrC0O3S 14.879 ns 0.0324 ns 0.0270 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4I 19.017 ns 0.0234 ns 0.0219 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4IHYQ 24.122 ns 0.0783 ns 0.0654 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4IHYQF4M 28.224 ns 0.0837 ns 0.0742 ns -
ISO/IEC 7064 MOD 1271-36 U7Y 3.993 ns 0.0239 ns 0.0223 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SX 5.886 ns 0.0195 ns 0.0173 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0 7.876 ns 0.0498 ns 0.0466 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3S 9.690 ns 0.0557 ns 0.0494 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4I 12.064 ns 0.0856 ns 0.0801 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4IHYQ 14.832 ns 0.0857 ns 0.0760 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4IHYQF4M 17.734 ns 0.1363 ns 0.1275 ns -
ISO/IEC 7064 MOD 37-2 U7Y 3.182 ns 0.0303 ns 0.0253 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SX 4.540 ns 0.0299 ns 0.0280 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0 6.188 ns 0.0817 ns 0.0764 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3S 6.959 ns 0.0358 ns 0.0299 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4I 8.238 ns 0.0535 ns 0.0474 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4IHYQ 9.840 ns 0.0572 ns 0.0507 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4IHYQF4M 10.781 ns 0.0573 ns 0.0508 ns -
ISO/IEC 7064 MOD 37,36 U7Y 3.191 ns 0.0277 ns 0.0231 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SX 4.903 ns 0.0462 ns 0.0432 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0 6.787 ns 0.1198 ns 0.1120 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3S 8.334 ns 0.0563 ns 0.0499 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4I 9.866 ns 0.0656 ns 0.0548 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4IHYQ 11.466 ns 0.0786 ns 0.0735 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4IHYQF4M 13.145 ns 0.0616 ns 0.0577 ns -
NOID Check Digit 11404/2h9 4.511 ns 0.0313 ns 0.0262 ns -
NOID Check Digit 11404/2h9tqb 6.029 ns 0.0305 ns 0.0285 ns -
NOID Check Digit 11404/2h9tqbxk6 7.134 ns 0.0436 ns 0.0407 ns -
NOID Check Digit 11404/2h9tqbxk6rw7 8.861 ns 0.0767 ns 0.0718 ns -
NOID Check Digit 11404/2h9tqbxk6rw7dwm 10.324 ns 0.0848 ns 0.0793 ns -
Value Specific Algorithms

Note: ABA RTN, CUSIP, ICAO 9303 multi-field algorithms (Machine Readable Visa, Size TD1, TD2 and TD3), ISAN, NHS, NPI and SEDOL algorithms do not support calculation of check digits, only validation of values containing check digits.

Algorithm Name Value Mean Error StdDev Allocated
IBAN BE00096123456769 12.797 ns 0.0626 ns 0.0586 ns -
IBAN GB00WEST12345698765432 22.264 ns 0.2030 ns 0.1695 ns -
IBAN SC00MCBL01031234567890123456USD 33.121 ns 0.1529 ns 0.1355 ns -
ICAO 9303 U7Y 4.193 ns 0.0450 ns 0.0421 ns -
ICAO 9303 U7Y8SX 5.840 ns 0.0395 ns 0.0370 ns -
ICAO 9303 U7Y8SXRC0 7.757 ns 0.1317 ns 0.1293 ns -
ICAO 9303 U7Y8SXRC0O3S 9.235 ns 0.0897 ns 0.0839 ns -
ICAO 9303 U7Y8SXRC0O3SC4I 11.032 ns 0.2064 ns 0.1723 ns -
ICAO 9303 U7Y8SXRC0O3SC4IHYQ 12.823 ns 0.0541 ns 0.0452 ns -
ICAO 9303 U7Y8SXRC0O3SC4IHYQF4M 14.776 ns 0.1006 ns 0.0941 ns -
ISIN AU0000XVGZA 7.917 ns 0.0690 ns 0.0645 ns -
ISIN GB000263494 7.118 ns 0.0536 ns 0.0475 ns -
ISIN US037833100 7.132 ns 0.0948 ns 0.0792 ns -
ISO 6346 CSQU305438 7.445 ns 0.0693 ns 0.0579 ns -
ISO 6346 MSKU907032 7.493 ns 0.0903 ns 0.0800 ns -
ISO 6346 TOLU473478 7.467 ns 0.0621 ns 0.0550 ns -
VIN 1G8ZG127_WZ157259 13.113 ns 0.0649 ns 0.0542 ns -
VIN 1HGEM212_2L047875 12.975 ns 0.0850 ns 0.0710 ns -
VIN 1M8GDM9A_KP042788 13.377 ns 0.1008 ns 0.0942 ns -

Validate Method

General Numeric Algorithms

All algorithms use a single check digit except ISO/IEC 7064 MOD 97-10 which uses two check digits.

Note that the Modulus10_1, Modulus10_2 and Modulus11 algorithms have a maximum length of 10 (including the check digit) for values being validated so their benchmarks do not cover lengths greater than 10.

Algorithm Name Value Mean Error StdDev Allocated
Damm 1402 2.107 ns 0.0153 ns 0.0144 ns -
Damm 1406622 3.959 ns 0.0172 ns 0.0160 ns -
Damm 1406625388 6.171 ns 0.0498 ns 0.0441 ns -
Damm 1406625380422 8.236 ns 0.0080 ns 0.0071 ns -
Damm 1406625380425518 11.350 ns 0.2009 ns 0.1879 ns -
Damm 1406625380425510280 14.888 ns 0.1275 ns 0.1130 ns -
Damm 1406625380425510282654 17.861 ns 0.1244 ns 0.1103 ns -
ISO/IEC�706 MOD�11,10 1409 2.482 ns 0.0221 ns 0.0196 ns -
ISO/IEC�706 MOD�11,10 1406623 4.196 ns 0.0318 ns 0.0297 ns -
ISO/IEC�706 MOD�11,10 1406625381 5.715 ns 0.0421 ns 0.0394 ns -
ISO/IEC�706 MOD�11,10 1406625380426 6.553 ns 0.0593 ns 0.0526 ns -
ISO/IEC�706 MOD�11,10 1406625380425514 8.079 ns 0.1089 ns 0.0909 ns -
ISO/IEC�706 MOD�11,10 1406625380425510286 9.670 ns 0.1054 ns 0.0934 ns -
ISO/IEC�706 MOD�11,10 1406625380425510282657 11.182 ns 0.0617 ns 0.0577 ns -
ISO/IEC�706�MOD 11-2 140X 2.074 ns 0.0171 ns 0.0152 ns -
ISO/IEC�706�MOD 11-2 1406628 3.803 ns 0.0240 ns 0.0213 ns -
ISO/IEC�706�MOD 11-2 1406625380 4.420 ns 0.0263 ns 0.0246 ns -
ISO/IEC�706�MOD 11-2 1406625380426 5.091 ns 0.0302 ns 0.0282 ns -
ISO/IEC�706�MOD 11-2 1406625380425511 5.880 ns 0.0254 ns 0.0225 ns -
ISO/IEC�706�MOD 11-2 140662538042551028X 6.881 ns 0.0434 ns 0.0385 ns -
ISO/IEC�706�MOD 11-2 1406625380425510282651 7.915 ns 0.0558 ns 0.0466 ns -
ISO/IEC�706 MOD�97-10 14066 2.411 ns 0.0131 ns 0.0122 ns -
ISO/IEC�706 MOD�97-10 14066262 4.086 ns 0.0298 ns 0.0264 ns -
ISO/IEC�706 MOD�97-10 14066253823 5.394 ns 0.0314 ns 0.0294 ns -
ISO/IEC�706 MOD�97-10 14066253804250 6.914 ns 0.0428 ns 0.0380 ns -
ISO/IEC�706 MOD�97-10 14066253804255112 8.808 ns 0.0543 ns 0.0508 ns -
ISO/IEC�706 MOD�97-10 14066253804255102853 10.441 ns 0.0491 ns 0.0460 ns -
ISO/IEC�706 MOD�97-10 14066253804255102826587 12.202 ns 0.0511 ns 0.0478 ns -
Luhn 1404 3.544 ns 0.0239 ns 0.0224 ns -
Luhn 1406628 4.607 ns 0.0323 ns 0.0286 ns -
Luhn 1406625382 6.550 ns 0.0597 ns 0.0558 ns -
Luhn 1406625380421 7.363 ns 0.0547 ns 0.0485 ns -
Luhn 1406625380425514 9.138 ns 0.0823 ns 0.0730 ns -
Luhn 1406625380425510285 10.409 ns 0.0735 ns 0.0614 ns -
Luhn 1406625380425510282651 12.164 ns 0.0669 ns 0.0626 ns -
Modulus10_13 1403 3.020 ns 0.0234 ns 0.0219 ns -
Modulus10_13 1406627 4.638 ns 0.0212 ns 0.0177 ns -
Modulus10_13 1406625385 5.447 ns 0.0333 ns 0.0311 ns -
Modulus10_13 1406625380425 6.674 ns 0.0399 ns 0.0333 ns -
Modulus10_13 1406625380425518 8.093 ns 0.0361 ns 0.0320 ns -
Modulus10_13 1406625380425510288 9.428 ns 0.0437 ns 0.0387 ns -
Modulus10_13 1406625380425510282657 10.903 ns 0.0325 ns 0.0304 ns -
Modulus10_1 1401 1.904 ns 0.0188 ns 0.0157 ns -
Modulus10_1 1406628 2.879 ns 0.0315 ns 0.0295 ns -
Modulus10_1 1406625384 4.125 ns 0.0316 ns 0.0295 ns -
Modulus10_2 1406 1.847 ns 0.0170 ns 0.0151 ns -
Modulus10_2 1406627 2.898 ns 0.0227 ns 0.0212 ns -
Modulus10_2 1406625389 4.048 ns 0.0270 ns 0.0253 ns -
Modulus11 1406 2.948 ns 0.0241 ns 0.0214 ns -
Modulus11 1406625 4.062 ns 0.0213 ns 0.0200 ns -
Modulus11 1406625388 4.506 ns 0.0278 ns 0.0247 ns -
Verhoeff 1401 4.827 ns 0.0255 ns 0.0239 ns -
Verhoeff 1406625 6.848 ns 0.0410 ns 0.0383 ns -
Verhoeff 1406625388 10.197 ns 0.0473 ns 0.0419 ns -
Verhoeff 1406625380426 13.644 ns 0.0384 ns 0.0340 ns -
Verhoeff 1406625380425512 17.068 ns 0.0725 ns 0.0643 ns -
Verhoeff 1406625380425510285 20.048 ns 0.0891 ns 0.0790 ns -
Verhoeff 1406625380425510282655 23.163 ns 0.0715 ns 0.0597 ns -
General Alphabetic Algorithms

ISO/IEC 7064 MOD 27,26 uses a single check character. ISO/IEC 7064 MOD 661-26 uses two check characters.

Algorithm Name Value Mean Error StdDev Allocated
ISO/IEC 7064 MOD 27,26 EGRS 2.332 ns 0.0226 ns 0.0211 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLU 4.097 ns 0.0308 ns 0.0273 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCB 5.679 ns 0.1293 ns 0.2195 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUA 7.347 ns 0.1623 ns 0.2379 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIKA 9.034 ns 0.1990 ns 0.4729 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIKNWWY 10.673 ns 0.1450 ns 0.1356 ns -
ISO/IEC 7064 MOD 27,26 EGRNMLJOCECUJIKNWWVVOQ 11.102 ns 0.1145 ns 0.0956 ns -
ISO/IEC 7064 MOD 661-26 EGRSE 2.641 ns 0.0136 ns 0.0121 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLDR 4.459 ns 0.0364 ns 0.0340 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCCK 6.448 ns 0.0262 ns 0.0245 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUZJ 8.374 ns 0.0898 ns 0.0796 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIKFQ 10.262 ns 0.0453 ns 0.0402 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIKNWWQN 13.125 ns 0.0858 ns 0.0760 ns -
ISO/IEC 7064 MOD 661-26 EGRNMLJOCECUJIKNWWVVORC 15.238 ns 0.0584 ns 0.0546 ns -
General Alphanumeric Algorithms

AlphanumericMod97_10 algorithm and ISO/IEC 7064 MOD 1271-36 uses two check characters. ISO/IEC 7064 MOD 37-2, ISO/IEC 7064 MOD 37,36 and NOID Check Digit algorithms use a single check character.

Note also that the values used for the NOID Check Digit algorithm do not include lengths 3 or 6 so that benchmarks are not run on purely numeric strings.

Algorithm Name Value Mean Error StdDev Allocated
AlphanumericMod97_10 U7y46 5.297 ns 0.0975 ns 0.0912 ns -
AlphanumericMod97_10 U7y8SX89 7.339 ns 0.0166 ns 0.0147 ns -
AlphanumericMod97_10 U7y8SXrC087 10.939 ns 0.0123 ns 0.0115 ns -
AlphanumericMod97_10 U7y8SXrC0O3S38 14.217 ns 0.0401 ns 0.0375 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4I27 18.788 ns 0.3287 ns 0.7553 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4IHYQ54 23.346 ns 0.0715 ns 0.0669 ns -
AlphanumericMod97_10 U7y8SXrC0O3Sc4IHYQF4M21 27.472 ns 0.0671 ns 0.0595 ns -
ISO/IEC 7064 MOD 1271-36 U7YM0 3.781 ns 0.0263 ns 0.0233 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXOR 5.045 ns 0.0353 ns 0.0330 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0FI 7.174 ns 0.0804 ns 0.0713 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SX4 9.202 ns 0.0654 ns 0.0580 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4I9D 11.000 ns 0.0479 ns 0.0424 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4IHYQYI 13.747 ns 0.0482 ns 0.0376 ns -
ISO/IEC 7064 MOD 1271-36 U7Y8SXRC0O3SC4IHYQF4M44 16.055 ns 0.0694 ns 0.0615 ns -
ISO/IEC 7064 MOD 37-2 U7YZ 2.688 ns 0.0120 ns 0.0100 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXV 4.350 ns 0.0338 ns 0.0299 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0E 5.145 ns 0.0262 ns 0.0245 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SU 6.425 ns 0.0441 ns 0.0391 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4IB 7.772 ns 0.0609 ns 0.0570 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4IHYQG 9.111 ns 0.0870 ns 0.0813 ns -
ISO/IEC 7064 MOD 37-2 U7Y8SXRC0O3SC4IHYQF4MF 10.416 ns 0.1256 ns 0.1113 ns -
ISO/IEC 7064 MOD 37,36 U7YW 3.189 ns 0.0284 ns 0.0252 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SX8 5.281 ns 0.0747 ns 0.0624 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0E 6.783 ns 0.0679 ns 0.0635 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SR 8.329 ns 0.0880 ns 0.0780 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4IT 9.865 ns 0.1457 ns 0.1292 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4IHYQD 11.894 ns 0.1117 ns 0.0990 ns -
ISO/IEC 7064 MOD 37,36 U7Y8SXRC0O3SC4IHYQF4MP 13.173 ns 0.0399 ns 0.0354 ns -
NOID Check Digit 11404/2h9m 5.089 ns 0.0247 ns 0.0219 ns -
NOID Check Digit 11404/2h9tqb0 6.419 ns 0.0417 ns 0.0369 ns -
NOID Check Digit 11404/2h9tqbxk6d 7.598 ns 0.0334 ns 0.0279 ns -
NOID Check Digit 11404/2h9tqbxk6rw74 8.816 ns 0.0623 ns 0.0552 ns -
NOID Check Digit 11404/2h9tqbxk6rw7dwmz 10.007 ns 0.0597 ns 0.0466 ns -
Value Specific Algorithms
Algorithm Name Value Mean Error StdDev Allocated
ABA RTN 111000025 4.572 ns 0.0099 ns 0.0088 ns -
ABA RTN 122235821 4.528 ns 0.0049 ns 0.0046 ns -
ABA RTN 325081403 4.526 ns 0.0029 ns 0.0022 ns -
CUSIP 37833100 6.268 ns 0.0053 ns 0.0049 ns -
CUSIP 38143VAA7 6.258 ns 0.0057 ns 0.0050 ns -
CUSIP 91282CJL6 6.258 ns 0.0073 ns 0.0065 ns -
FIGI BBG000B9Y5X2 7.885 ns 0.0056 ns 0.0050 ns -
FIGI BBG111111160 7.929 ns 0.0053 ns 0.0045 ns -
FIGI BBGZYXWVTSR7 8.047 ns 0.0575 ns 0.0537 ns -
IBAN BE71096123456769 11.903 ns 0.0768 ns 0.0718 ns -
IBAN GB82WEST12345698765432 21.263 ns 0.2220 ns 0.2076 ns -
IBAN SC74MCBL01031234567890123456USD 32.737 ns 0.3820 ns 0.3190 ns -
ICAO 9303 U7Y5 4.321 ns 0.0208 ns 0.0195 ns -
ICAO 9303 U7Y8SX8 6.020 ns 0.0632 ns 0.0591 ns -
ICAO 9303 U7Y8SXRC03 7.693 ns 0.0856 ns 0.0801 ns -
ICAO 9303 U7Y8SXRC0O3S8 9.483 ns 0.2059 ns 0.2749 ns -
ICAO 9303 U7Y8SXRC0O3SC4I2 10.983 ns 0.0744 ns 0.0696 ns -
ICAO 9303 U7Y8SXRC0O3SC4IHYQ9 12.690 ns 0.0482 ns 0.0427 ns -
ICAO 9303 U7Y8SXRC0O3SC4IHYQF4M8 14.541 ns 0.0988 ns 0.0876 ns -
ICAO 9303 Machine Readable Visa I<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<br>D231458907UTO7408122F1204159<<<<<<<< 19.684 ns 0.1291 ns 0.1207 ns -
ICAO 9303 Machine Readable Visa I<UTOSKYWALKER<<LUKE<<<<<<<<<<<<<<<<<br>STARWARS45UTO7705256M2405252<<<<<<<< 19.651 ns 0.1502 ns 0.1405 ns -
ICAO 9303 Machine Readable Visa V<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<<<<<<<<<br>L898902C<3UTO6908061F9406236ZE184226B<<<<<<< 18.538 ns 0.2393 ns 0.1998 ns -
ICAO 9303 Size TD1 I<UTOD231458907<<<<<<<<<<<<<<<<br>7408122F1204159UTO<<<<<<<<<<<6<br>ERIKSSON<<ANNA<MARIA<<<<<<<<<< 33.773 ns 0.1454 ns 0.1289 ns -
ICAO 9303 Size TD1 I<UTOSTARWARS45<<<<<<<<<<<<<<<<br>7705256M2405252UTO<<<<<<<<<<<4<br>SKYWALKER<<LUKE<<<<<<<<<<<<<<< 38.206 ns 0.1840 ns 0.1631 ns -
ICAO 9303 Size TD1 I<UTOD23145890<AB112234566<<<<<br>7408122F1204159UTO<<<<<<<<<<<4<br>ERIKSSON<<ANNA<MARIA<<<<<<<<<< 34.386 ns 0.2079 ns 0.1945 ns -
ICAO 9303 Size TD2 I<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<br>D231458907UTO7408122F1204159<<<<<<<6 31.622 ns 0.2665 ns 0.2492 ns -
ICAO 9303 Size TD2 I<UTOQWERTY<<ASDF<<<<<<<<<<<<<<<<<<<<br>D23145890<UTO7408122F1204159AB1124<4 31.700 ns 0.2532 ns 0.2368 ns -
ICAO 9303 Size TD2 I<UTOSKYWALKER<<LUKE<<<<<<<<<<<<<<<<<br>STARWARS45UTO7705256M2405252<<<<<<<8 31.443 ns 0.1810 ns 0.1604 ns -
ICAO 9303 Size TD3 P<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<<<<<<<<<br>L898902C36UTO7408122F1204159ZE184226B<<<<<10 41.579 ns 0.2136 ns 0.1998 ns -
ICAO 9303 Size TD3 P<UTOQWERTY<<ASDF<<<<<<<<<<<<<<<<<<<<<<<<<<<<br>Q123987655UTO3311226F2010201<<<<<<<<<<<<<<06 44.731 ns 0.1975 ns 0.1847 ns -
ICAO 9303 Size TD3 P<UTOSKYWALKER<<LUKE<<<<<<<<<<<<<<<<<<<<<<<<<br>STARWARS45UTO7705256M2405252HAN<SHOT<FIRST78 44.764 ns 0.2196 ns 0.1947 ns -
ISAN C594660A8B2E5D22X6DDA3272E 18.823 ns 0.2636 ns 0.2336 ns -
ISAN D02C42E954183EE2Q1291C8AEO 17.367 ns 0.1634 ns 0.1364 ns -
ISAN E9530C32BC0EE83B269867B20F 16.964 ns 0.1627 ns 0.1442 ns -
ISAN (Formatted) ISAN C594-660A-8B2E-5D22-X 15.646 ns 0.1663 ns 0.1474 ns -
ISAN (Formatted) ISAN D02C-42E9-5418-3EE2-Q 14.682 ns 0.1183 ns 0.1049 ns -
ISAN (Formatted) ISAN E953-0C32-BC0E-E83B-2 15.727 ns 0.1711 ns 0.1516 ns -
ISAN (Formatted) ISAN C594-660A-8B2E-5D22-X-6DDA-3272-E 24.230 ns 0.2041 ns 0.1909 ns -
ISAN (Formatted) ISAN D02C-42E9-5418-3EE2-Q-1291-C8AE-O 25.131 ns 0.1821 ns 0.1614 ns -
ISAN (Formatted) ISAN E953-0C32-BC0E-E83B-2-6986-7B20-F 25.201 ns 0.1258 ns 0.1051 ns -
ISIN AU0000XVGZA3 7.816 ns 0.0852 ns 0.0797 ns -
ISIN GB0002634946 7.346 ns 0.0458 ns 0.0428 ns -
ISIN US0378331005 7.348 ns 0.0563 ns 0.0526 ns -
ISO 6346 CSQU3054383 7.957 ns 0.0592 ns 0.0554 ns -
ISO 6346 MSKU9070323 7.953 ns 0.0625 ns 0.0554 ns -
ISO 6346 TOLU4734787 7.950 ns 0.0467 ns 0.0437 ns -
NHS 4505577104 4.584 ns 0.0319 ns 0.0298 ns -
NHS 5301194917 4.577 ns 0.0302 ns 0.0268 ns -
NHS 9434765919 4.574 ns 0.0262 ns 0.0245 ns -
NPI 1122337797 6.099 ns 0.0248 ns 0.0232 ns -
NPI 1234567893 6.748 ns 0.0648 ns 0.0574 ns -
NPI 1245319599 6.038 ns 0.0320 ns 0.0267 ns -
SEDOL 3134865 5.849 ns 0.0271 ns 0.0240 ns -
SEDOL B0YQ5W0 5.872 ns 0.0328 ns 0.0291 ns -
SEDOL BRDVMH9 5.860 ns 0.0361 ns 0.0302 ns -
VIN 1G8ZG127XWZ157259 13.278 ns 0.0645 ns 0.0538 ns -
VIN 1HGEM21292L047875 13.297 ns 0.0520 ns 0.0434 ns -
VIN 1M8GDM9AXKP042788 12.869 ns 0.0624 ns 0.0521 ns -

Validate Method (with ICheckDigitMask)

The following implementation of ICheckDigitMask is used for the benchmarks:

public class GroupsOfThreeCheckDigitMask : ICheckDigitMask
{
   public Boolean ExcludeCharacter(Int32 index) => (index + 1) % 4 == 0;

   public Boolean IncludeCharacter(Int32 index) => (index + 1) % 4 != 0;
}
General Numeric Algorithms
Algorithm Name Value Mean Error StdDev Allocated
Luhn 140 4 4.647 ns 0.0278 ns 0.0232 ns -
Luhn 140 662 8 6.048 ns 0.0490 ns 0.0458 ns -
Luhn 140 662 538 2 8.229 ns 0.0595 ns 0.0528 ns -
Luhn 140 662 538 042 1 9.500 ns 0.0665 ns 0.0622 ns -
Luhn 140 662 538 042 551 4 11.272 ns 0.0564 ns 0.0528 ns -
Luhn 140 662 538 042 551 028 5 13.034 ns 0.0692 ns 0.0613 ns -
Luhn 140 662 538 042 551 028 265 1 14.754 ns 0.1212 ns 0.1075 ns -

Release History/Release Notes

v1.0.0-alpha

Initial limited release. Included algorithms:

  • ABA RTN (Routing Transit Number) Algorithm
  • Damm Algorithm
  • ISIN (International Securities Identification Number) Algorithm
  • Luhn Algorithm
  • Modulus10_1 Algorithm
  • Modulus10_2 Algorithm
  • Modulus10_13 Algorithm (UPC/EAN/ISBN-13/etc.)
  • Modulus11 Algorithm (ISBN-10/ISSN/etc.)
  • NHS (UK National Health Service) Algorithm
  • NPI (US National Provider Identifier) Algorithm
  • Verhoeff Algorithm
  • VIN (Vehicle Identification Number) Algorithm

v1.0.0

Initial release. Additional included algorithms

  • ISO/IEC 7064 MOD 11,10
  • ISO/IEC 7064 MOD 11-2
  • ISO/IEC 7064 MOD 1271-36
  • ISO/IEC 7064 MOD 27,26
  • ISO/IEC 7064 MOD 37-2
  • ISO/IEC 7064 MOD 37,36
  • ISO/IEC 7064 MOD 661-26
  • ISO/IEC 7064 MOD 97-10

v1.1.0

Additional included algorithms

  • AlphanumericMod97_10Algorithm
  • IbanAlgorithm
  • IsanAlgorithm (including ValidateFormatted method)
  • NcdAlgorithm (NOID Check Digit)

Performance increases for:

  • ISO/IEC 7064 MOD 1271-36, Validate method ~18% improvement
  • ISO/IEC 7064 MOD 37-2, Validate method ~17% improvement, TryCalculateCheckDigit method ~20% improvement
  • ISO/IEC 7064 MOD 37-36, Validate method ~18% improvement, TryCalculateCheckDigit method ~21% improvement

v2.0.0

Updated to .Net 8.0

Average performance improvement for .Net 8.0 across all algorithms: Validate method ~8% improvement, TryCalculateCheckDigit method ~4.9% improvement

Detailed benchmark results for .Net 7 vs .Net 8 located at https://github.com/KnowledgeForwardSolutions/CheckDigits.Net/blob/main/Documentation/DotNet7_DotNet8_PerformanceComparision.md

v2.1.0

Additional included algorithms

  • CUSIP Algorithm
  • ISO 6346 Algorithm
  • SEDOL Algorithm

Performance increases for:

  • Luhn Algorithm, Validate method ~15% improvement over .Net 7, TryCalculateCheckDigit method ~27% improvement over .Net 7 (Luhn algorithm originally saw a slight performance decrease when switching from .Net 7 to .Net 8. This release addresses that performance decrease.)
  • Damm Algorithm, Validate and TryCalculateCheckDigit methods ~30% improvement
  • Verhoeff Algorithm, Validate method ~20% improvement, TryCalculateCheckDigit method ~30% improvement

v2.2.0

Support for netstandard2.0

Thanks to Steff Beckers for this addition

v2.3.0

Additional included algorithms

  • FIGI Algorithm
  • ICAO Algorithm
  • ICAO 9303 Document Size TD1 Algorithm
  • ICAO 9303 Document Size TD2 Algorithm
  • ICAO 9303 Document Size TD3 Algorithm
  • ICAO 9303 Machine Readable Visa Algorithm

Performance increases for:

  • AlphanumericMod97_10Algorithm, Validate method ~15% improvement, TryCalculateCheckDigits method ~8% improvement
  • IBAN Algorithm, Validate method ~8% improvement
  • ISIN algorithm, ~9% improvement for Validate and TryCalculateCheckDigit methods
  • ISO/IEC 7064 MOD 1271-36, TryCalculateCheckDigits method ~8% improvement
  • NcdAlgorithm (NOID Check Digit), minimum 10% improvement for Validate method, improvement increases with length of value.
  • NpiAlgorithm, Validate method ~8 improvement

v2.3.1

Documentation update. Fix several minor documentation errors in README file. No code changes.

v3.0.0

Updated to .Net 10.0

Average performance improvement for .Net 10.0 across all algorithms is ~4% for both Validate and TryCalculateCheckDigit methods.

Detailed benchmark results for .Net 8 vs .Net 10 located at https://github.com/KnowledgeForwardSolutions/CheckDigits.Net/blob/main/Documentation/DotNet8_DotNet10_PerformanceComparision.md

Added masked validation support for algorithms via ICheckDigitMask and IMaskedCheckDigitAlgorithm interfaces. Algorithms that implement IMaskedCheckDigitAlgorithm:

  • Luhn Algorithm
Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
.NET Core netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen40 was computed.  tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

  • .NETStandard 2.0

  • net10.0

    • No dependencies.

  • net8.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
3.0.0 151 12/30/2025
2.3.1 70,417 5/15/2024
2.3.0 212 5/14/2024
2.2.0 23,921 1/25/2024
2.1.0 320 12/5/2023
2.0.0 241 11/21/2023
1.1.0 225 11/18/2023
1.0.0 316 10/26/2023
1.0.0-alpha 219 10/14/2023

## 1.0.0-alpha

Initial limited release. Included algorithms:
* ABA RTN (Routing Transit Number) Algorithm
* Damm Algorithm
* ISIN (International Securities Identification Number) Algorithm
* Luhn Algorithm
* Modulus10_1 Algorithm
* Modulus10_2 Algorithm
* Modulus10_13 Algorithm (UPC/EAN/ISBN-13/etc.)
* Modulus11 Algorithm (ISBN-10/ISSN/etc.)
* NHS (UK National Health Service) Algorithm
* NPI (US National Provider Identifier) Algorithm
* Verhoeff Algorithm
* VIN (Vehicle Identification Number) Algorithm

## 1.0.0

Initial release. Additional included algorithms
* ISO/IEC 7064 MOD 11,10
* ISO/IEC 7064 MOD 11-2
* ISO/IEC 7064 MOD 1271-36
* ISO/IEC 7064 MOD 27,26
* ISO/IEC 7064 MOD 37-2
* ISO/IEC 7064 MOD 37,36
* ISO/IEC 7064 MOD 661-26
* ISO/IEC 7064 MOD 97-10

## v1.1.0

Additional included algorithms
* AlphanumericMod97_10Algorithm
* IbanAlgorithm
* IsanAlgorithm (including ValidateFormatted method)
* NcdAlgorithm (NOID Check Digit)

Performance increases for:
* ISO/IEC 7064 MOD 1271-36, Validate method ~18% improvement
* ISO/IEC 7064 MOD 37-2, Validate method ~17% improvement, TryCalculateCheckDigit method ~20% improvement
* ISO/IEC 7064 MOD 37-36, Validate method ~18% improvement, TryCalculateCheckDigit method ~21% improvement

## v2.0.0

Updated to .Net 8.0

Average performance improvement for .Net 8.0 across all algorithms:
 Validate method ~8% improvement, TryCalculateCheckDigit method ~4.9% improvement

## v2.1.0

Additional included algorithms
* CUSIP Algorithm
* ISO 6346 Algorithm
* SEDOL Algorithm

Performance increases for:
* Luhn Algorithm, Validate method ~15% improvement over .Net 7, TryCalculateCheckDigit method ~27% improvement over .Net 7
 (Luhn algorithm originally saw a slight performance decrease when switching from .Net 7 to .Net 8. This release addresses that performance decrease.)
* Damm Algorithm, Validate and TryCalculateCheckDigit methods ~30% improvement
* Verhoeff Algorithm, Validate method ~20% improvement, TryCalculateCheckDigit method ~30% improvement

## v2.2.0

Support for netstandard2.0

Thanks to Steff Beckers for this addition

## v2.3.0

Additional included algorithms
* FIGI Algorithm
* ICAO Algorithm
* ICAO 9303 Document Size TD1 Algorithm
* ICAO 9303 Document Size TD2 Algorithm
* ICAO 9303 Document Size TD3 Algorithm
* ICAO 9303 Machine Readable Visa Algorithm

Performance increases for:
* AlphanumericMod97_10Algorithm, Validate method ~15% improvement, TryCalculateCheckDigits method ~8% improvement
* IBAN Algorithm, Validate method ~8% improvement
* ISIN algorithm, ~9% improvement for Validate and TryCalculateCheckDigit methods
* ISO/IEC 7064 MOD 1271-36, TryCalculateCheckDigits method ~8% improvement
* NcdAlgorithm (NOID Check Digit), minimum 10% improvement for Validate method, improvement increases with length of value.
* NpiAlgorithm, Validate method ~8 improvement

## v2.3.1

Documentation update. Fix several minor documentation errors in README file. No code changes.

## v3.0.0

Updated to .Net 10.0

Average performance improvement for .Net 10.0 across all algorithms is ~4% for
both Validate and TryCalculateCheckDigit methods.

Detailed benchmark results for .Net 8 vs .Net 10 located at https://github.com/KnowledgeForwardSolutions/CheckDigits.Net/blob/main/Documentation/DotNet8_DotNet10_PerformanceComparision.md

Added masked validation support for algorithms via ICheckDigitMask and IMaskedCheckDigitAlgorithm interfaces. Algorithms that implement IMaskedCheckDigitAlgorithm:
* Luhn Algorithm