MagTek MagneSafe V5 User Manual

Page 129

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Appendix D. Command Examples

121

F0FEAE7908801093 TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets 47796C85E4CE30FF
XOR 724C5DB7D6F901C7
gets 3535313232373138 (decrypted block 2)

Continue on in reverse block order:
724C5DB7D6F901C7 TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets 3B35343532333030 (decrypted block 1)

Ordering the decrypted blocks 1st to last we get:
HEX ASCII
3B35343532333030 ;5452300
3535313232373138 55122718
393D303830343332 9=080432
3130303030303030 10000000
373235303F000000 7250?

We can ignore the last three bytes because they are all hex 00 and fall
after the End Sentinel.

ASCII string ";5452300551227189=080432100000007250?"

This is an accurate decryption of the track.


Track 3 encrypted data
Block # 1 E31234A91059A0FB
2 FE627954EE21868A
3 EE3979540B67FCC4
4 0F61CECA54152D1E

Appendix C tells us to decrypt the last block:
0F61CECA54152D1E TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets DE0949643B57C3C4
XOR EE3979540B67FCC4
gets 3030303030303F00 (decrypted last block)

Continue on in reverse block order:
EE3979540B67FCC4 TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets CB5F4964DE11B6BA
XOR FE627954EE21868A
gets 353D303030303030 (decrypted block 3)

Continue on in reverse block order:
FE627954EE21868A TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets D32A0499226994CF
XOR E31234A91059A0FB
gets 3038303032303434 (decrypted block 2)

Continue on in reverse block order:
E31234A91059A0FB TDES Dec with 27F66D5244FF621E AA6F6120EDEB427F
gets 2B35313633343939 (decrypted block 1)

Ordering the decrypted blocks 1st to last we get:
HEX ASCII
2B35313633343939 +5163499
3038303032303434 08002044
353D303030303030 3=000000
3030303030303F00 000000?

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