IBM 2 Performing the Special Encryption and Special Decryption Processes

CCA Release 2.54
The following is an example of calculating the current PIN encrypting key:
Wa = X'4567 89AB CDE '
Ca = X'11'
Sa1 = X'1'
Ta1 = X'4567 89AB CDF '
Tb1 = X'6489 F5A3 1618 2AB'
Tc1 = X'F9AC C638 1939 44BC'
Ka2 = X'D842 BA3 C2D1 6417'
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.
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Sa20 = X'1'
Ta20 = X'4567 89AB CDF 1'
Tb20 = X'9D25 339B F21 6416'
Tc20 = X'BF49 836E AE2A 42A'
Ka20 = X'67B 395E 6CFB 63D'
Current PIN encrypting key = X'67B 395E 6CFB 6C2'
Performing the Special Encryption and Special Decryption Processes
The special encryption process consists of the following steps:
1. Name the derived unique key for the current transaction Ku.
2. Name the clear PIN-block that was built from the user-entered PIN Pc.
3. Perform an XOR operation with the rightmost byte of Ku and X'FF' to produce
a variant of the key; name the result Kuv.
4. Perform an XOR operation with Kuv and Pc; store the result in T1.
5. Encrypt T1 with Kuv; store the result in T2.
6. Perform an XOR operation with Kuv; store the result in Pe.
The value in Pe is the encrypted PIN-block that the POS terminal will send.
The special decryption process consists of these steps, in reverse.
The following is an example of the special encryption process:
Current encrypting key = Ku = X'67B 395E 6CFB 63D'
User-entered PIN = 1234
User’s primary account-number = X'412 3456 789'
Clear PIN-block (unformatted) = X'412 34FF FFFF FFFF'
Primary account-number (formatted) = X' 412 3456 789'
Clear PIN-block (ANSI format) = Pc = X'412 74ED CBA9 876F'
Variant of PIN encrypting key = Kuv = X'67B 395E 6CFB 6C2'
T1 = X'6319 4DB3 A752 E7AD'
T2 = X'5145 3CA3 E474 2148'
Pe = X'364E 5FD 888F 418A'
Appendix E. Financial System Verbs Calculation Methods and Data Formats E-15