Generating a Check Value

Command: CK (Generate KCV). Can be used in online, offline or secure state.

Function:     To generate a key check value (KCV) for a key encrypted under a specified LMK pair.

Inputs:        Encrypted key (under the relevant LMK pair):

·         Single-length key: 16 hexadecimal characters.

·         Double-length key:  32 hex characters or 1 alpha + 32 hex characters.

·         Triple-length key: 1 alpha + 48 hex

Key-Type: a code indicating the type of key that is to be input, 3 decimal digits. See Key Type Table.

Outputs:     The check value: 16 hexadecimal characters.

Errors:        Data invalid; please re-enter: - incorrect number of characters.

Key parity error; re-enter key: - the entered key does not have odd parity on each byte. Re-enter the complete line (key and Key-Type code) and check for typographic errors.

Invalid key type; re-enter: - the key type is invalid.  See Key Type Table.

Internal failure 12: function aborted - the contents of LMK storage have been corrupted or erased. Do not continue. Inform the Security Department.

Example:

Online> CK <Return>

Enter key type code: NNN <Return>

Enter key length flag [S/D/T]: S <Return>

                             or

             D <Return>

                             or

             T <Return>

Enter encrypted key: XXXX XXXX XXXX XXXX <Return>

                                   or

YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY <Return>

                                   or

T YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY YYYY

                                   (as applicable)

Key check value: ZZZZ ZZZZ ZZZZ ZZZZ