BS ISO/IEC 7064:2003

1 Scope
2 Terms and definitions
3 Symbols and notation
4 Types of systems
   4.1 Pure systems
   4.2 Hybrid systems
5 Compliance and designation
   5.1 Strings
   5.2 Check character generating products
   5.3 Checking products
   5.4 System designation
6 Specification of pure systems
   6.1 Formula
   6.2 Calculation
   6.3 Check character position
7 Computational methods for pure systems with one check
   character
   7.1 Pure system recursive method
        7.1.1 Computation
        7.1.2 Example
   7.2 Pure system polynomial method
        7.2.1 Computation
        7.2.2 Example
8 Computational methods for pure systems with two check
   characters
   8.1 Computation
   8.2 Example using recursive method
   8.3 Example using polynomial method
   8.4 Simplified procedure for ISO/IEC 7064, MOD 97-10
9 Specification for hybrid systems
   9.1 Formula
   9.2 Check character position
10 Computational method for hybrid systems
   10.1 Hybrid system recursive method
        10.1.1 Computation
        10.1.2 Example
Annex A (informative) Criteria for the selection of check
        character system for applications
Annex B (informative) Check character systems for other
        alphabets
Bibliography

Provides a set of check character systems capable of protecting strings against errors which occur when people copy or type data. Defines conformance requirements for products described as generating check characters or checking strings using the systems given.

1.1 This International Standard specifies a set of check character systems capable of protecting strings against errors which occur when people copy or type data. The strings may be of fixed or variable length and may have character sets which are numeric (10 digits: 0 to 9); alphabetic (26 letters: A to Z); and alphanumeric (letters and digits). Embedded spaces and special characters are ignored. 1.2 This International Standard specifies conformance requirements for products described as generating check characters or checking strings using the systems given in this International Standard. 1.3 These check character systems can detect: all single substitution errors (the substitution of a single character for another, for example “4234” for “1234)”; all or nearly all single (local) transposition errors (the transposition of two single characters, either adjacent or with one character between them, for example “12354” or “12543” for “12345”); all or nearly all circular shift errors (circular shifts of the whole string to the left or right); a high proportion of double substitution errors (two separate single substitution errors in the same string, for example “7234587” for “1234567)”; and a high proportion of all other errors. 1.4 This International Standard excludes systems designed specifically to: permit both error detection and automatic correction; detect deliberate falsification; and check strings interchanged solely between machines. 1.5 This International Standard is for use in information interchange between organizations. It is also strongly recommended for use in internal information systems.