ive no idea what to call it.

Hello,
ive got some information that i think some of you ciphers can help me with .. i'm not much of one at all.. so if i use terms that seem idiotic.. just disregard them..
well here it goes.
.. The first "7ASA9602" number is a sort of serial number to a VSM program (Video Store Manager) ...after that number is given it looks for that larger string of numbers "31FWD1SPSV73PA8:8OUSOBBWDT3THQKB" to be inputed into a computer that lets you enter the program.. a sort of key... For each machine (with diffrent hardware) diffrent 8 character number is given to me.. and it waits for the 32 character number in return... i wish to know how the program uses the 8 character key to check the 32 key.. and if it is possible to sum-what crack the code...also the " : " character is included in the 32 character key.

7A2A9602
31FWD1SPSV73PA8:8OUSOBBWDT3THQKB

A9624702
31TBAIVLXP8KUY35BMXDR:LAHC75XLK3

75BA9602
31NJJ1QSY37OEI8:8JECQ6JSWXCTCNHB

14F44480
22NXF:IRFA6BI6463LMAN6YETGHDCCH6

81F13702
42TAR2PLYG9VCY35:RQRS3ACMAHIVQX3

A6D030F1
21DQF6CVXI1AMX24BTVBN7HLTWEDQLI1

18CF9161
21ALW7IFRN2MSB8:2YT339QBQGDEPAIG

..all characters are in caps... and there are some patterns in the numbers.. such as the
A9624702
75BA9602
the 702 and the 602...
If anyone can figure how it all works.. please post something.
thank you very much for your time.. it is much appreciated.

-Lorenzo