KCV was wrong.

May 16, 2012 at 5:41 PM
Edited May 16, 2012 at 10:40 PM

Hello,
I encrypted a test key on Thales Simulator and the KCV was wrong "0000 00", I computed the KCV in my personal program and the result is 8CA64D.

The information used is below.

Connected - Type in commands followed by ENTER.
FK
Key length [1,2,3]: 2
Key Type: 001
Key Scheme: U
Component type [X,H,E,S]: X
Enter number of components (2-9): 2
Enter component #1: 01010101010101010101010101010101
Enter component #2: 00000000000000000000000000000000
Encrypted key: U 37A8 3AAF F387 1918 46A7 1CD6 6928 9ACC
Key check value: 0000 00

Coordinator
May 16, 2012 at 5:52 PM

When the simulator's DES algorithm is used with weak or semi-weak keys (such as the key you're trying to use), an error occurs. In these cases, the algorithm does not encrypt/decrypt the data but returns it back to the caller. Since a KCV is calculated by encrypting zeroes with the key, you'll get zeroes when using a weak or semi-weak key.

May 16, 2012 at 11:23 PM

Hello, Nickntg.
Thanks for your response.
I was trying other keys and in this case, the return is different of zeros.

Look below.

Connected - Type in commands followed by ENTER.
Fk
Command not found
FK
Key length [1,2,3]: 2
Key Type: 109
Key Scheme: U
Component type [X,H,E,S]: X
Enter number of components (2-9): 2
Enter component #1: 10101010101010101010101010101010
Enter component #2: 00000000000000000000000000000000
Encrypted key: U FCBE 4E32 4AD8 6FB2 8A25 7593 BE61 655B
Key check value: 82E1 36

Coordinator
May 17, 2012 at 6:16 AM

Is this a weak or semi-weak key?