ISO/IEC 7064:2003

Overview

ISO/IEC 7064:2003 - Information technology - Security techniques - Check character systems - defines a validated set of check character (check digit/checksum) systems for protecting human-entered strings against transcription and keying errors. It covers numeric, alphabetic and alphanumeric strings (embedded spaces and special characters are ignored), specifies conformance requirements for products that generate or check check characters, and is intended for information interchange between organizations as well as internal systems.

Key topics and requirements

• Scope of protection: systems specified can detect
  • all single substitution errors (one character changed),
  • all or nearly all single local transposition errors (adjacent or with one character between),
  • circular shift (left/right) errors,
  • a high proportion of double substitutions and other errors.
• Exclusions: ISO/IEC 7064 is not intended to permit automatic error correction, detect deliberate falsification, or cover strings exchanged exclusively between machines.
• System types
  • Pure systems (single modulus for all stages): e.g. MOD 11–2, MOD 37–2, MOD 97–10, MOD 661–26, MOD 1271–36. These can produce one or two check characters; some produce a supplementary character outside the protected character set (e.g., “X”).
  • Hybrid systems (two moduli, one equal to character-set size and one one greater): e.g. MOD 11,10, MOD 27,26, MOD 37,36. Hybrid systems always return a check character within the original character set.
• Placement & computation
  • Check character(s) are placed at the rightmost end of the string.
  • Standard specifies the mathematical formula using modulus and radix (geometric progression) and two computational methods: recursive and polynomial; both are equivalent in result.
• Conformance and designation
  • Product descriptions must state which ISO/IEC 7064 systems they generate/check (full designation recommended, single-digit codes allowed for brevity).

Practical applications

• Prevent transcription/keying errors in identifiers such as account numbers, membership IDs, product codes, serial numbers and reference numbers exchanged between organizations.
• Useful where human data entry or copy/scan of codes is common and high error-detection capability is required.
• Selected by system architects, software developers, database designers, standards compliance teams, and IT security practitioners to improve data integrity in business processes.

Who should use this standard

• Banks, financial services, publishing, supply chain, registration authorities, and software vendors that handle human-entered identifiers.
• Developers and QA teams implementing check-digit validation or generating check characters in applications and APIs.

Related standards

• ISO 2108, ISO 6166 (other identifier-related standards). Note: ISO 2894 has been withdrawn. ISO/IEC 7064 supersedes ISO 7064:1983 with technical revisions.