201206260054 vmc38
explained decrypted manual
Operator test: 22 GUIDs, seed 317. 3DES, key MD5(name).
From the post to its content
As posted (encrypted)
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
- Read the ciphertext. Strip whitespace: 1,424 hex characters = 712 bytes = 89 8-byte 3DES blocks.
- Derive the key. Password =
A858DE45F56D9BC9(name). Key = MD5(password) =34a14a42e98ff96095af56604e290cae, used as a two-key 3DES key. - Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 22 GUIDs as hex (shown below).
Decrypted: GUID list
1 ca22fbed-4a10-3d58-ae85-312a07ea25ea 2 425022af-09f0-7d2e-940d-81b95c8bbf2d 3 a2e09f7a-2d09-3daa-b0f2-0ce22c243689 4 d24ac35b-887a-1bfb-a582-20c55169b881 5 30984ade-0fc5-26b5-a7a2-29ac2ea956b2 6 1fed318d-df49-593c-8c12-1b873b60003f 7 1d889743-830a-88b5-8e7c-3b7546569eb6 8 1512c667-3db6-44a7-a11f-38365481cae1 9 d00ea996-40d5-114f-be1a-6e9771a911ad 10 7dd05d41-58c6-19de-924b-1585241480d8 11 ebcd0606-1d48-7716-9185-bdf5c567f2cb 12 f65691da-9f8c-80b8-9019-505570096cf6 13 021fa5d7-3d93-4149-9601-b968080c906c 14 3eca40bc-35eb-3feb-9ad9-07239d3fd9dd 15 8464654a-8442-73ac-9446-a059c53ea9fa 16 fa034ad3-8e99-09f4-845b-015d40176b58 17 95c2e51e-0b27-1389-851c-2694afebcb6e 18 66eddab0-86db-4bd1-bf67-829e07fd5b49 19 26f40ca1-3acb-29a1-9f1f-f493513dda40 20 ef4a9d17-b10e-04d4-b28d-5a7a63a11fa3 21 24f966c6-43ac-8e6e-a0bb-2654b5043c30 22 36b9c4c2-52d2-5fef-989e-04329457eeec
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
3731258411784370142085. Exactly this sequence comes out ofnew Random(317).Next(9): the per-post millisecond seed of the mask generator. The other 30 hex digits of each GUID areGuid.NewGuid()output and carry no message. - Explain the count. Grouped in Operator tests, 2012-06-26: operator test session in true Pacific time (morning burst, pairs seconds apart; 15:10/15:13 and 17:37/17:38 pairs just before the 15:25 and 17:45 app starts)
- Conclusion. Filler. The content is fully explained by the two RNGs.
Solution summary
- Method
- MD5(name) ECB
- Result
- 3DES(name) ECB, 22 GUIDs, seed 317
- Explanation
- Pre-cutover filler under MD5(name) ECB: operator test session in true Pacific time (morning burst, pairs seconds apart; 15:10/15:13 and 17:37/17:38 pairs just before the 15:25 and 17:45 app starts); list seed 317 from the GUID masks (3DES(name) ECB, 22 GUIDs, seed 317)