ISO/IEC 7064:2003
Information technology -- Security techniques -- Check character systems
Product Details
- numeric (10 digits: 0 to 9);
- alphabetic (26 letters: A to Z);
- alphanumeric (letters and digits).
Embedded spaces and special characters are ignored.
ISO/IEC 7064:2002 specifies conformance requirements for products described as generating check characters or checking strings using the systems given in this International Standard.
ISO/IEC 7064:2002 is for use in information interchange between organizations; it is also strongly recommended as good practice for internal information systems.
The check character systems specified in ISO/IEC 7064:2002 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 shift errors (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);
- a high proportion of all other errors.
ISO/IEC 7064:2002 excludes systems designed specifically to:
- permit both error detection and automatic correction;
- detect deliberate falsification;
- check strings interchanged solely between machines.
ISO/IEC 7064:2002 specifies two types of systems:
- pure systems;
- hybrid systems.
The pure systems use a single modulus for all stages of the calculation.