201207271411 x9n1l
explained decrypted filler
3DES(name+name) ECB, 25 GUIDs, seed 703
From the post to its content
As posted (encrypted)
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
- Read the ciphertext. Strip whitespace: 1,616 hex characters = 808 bytes = 101 8-byte 3DES blocks.
- Derive the key. Password =
A858DE45F56D9BC9A858DE45F56D9BC9(name+name). Key = MD5(password) =0dcc4bd9e114ebc42078977dc9125404, used as a two-key 3DES key. - Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 25 GUIDs as hex (shown below).
Decrypted: GUID list
1 04facf24-2bf5-856c-8d12-5bac8d7b5e12 2 5b37d49c-5357-0a44-939f-20e9afff0348 3 ec3046cc-8210-1916-b5b5-a62dd2c93cb5 4 83c3fdb5-8d11-5dca-a2fa-a7a967c35d5a 5 f047d8de-7502-5ca5-9f91-8e05ba507c2f 6 7c3ab320-7873-8756-8f8f-6a5a6946b446 7 0aae583f-1802-8334-a340-602300e127dc 8 8acd370a-dee9-1717-aca2-0634ee129953 9 fb7f6525-21b6-8acf-8402-b4e12aa8700d 10 3fb70fc8-f31a-4cdd-8efa-2a267d57f90f 11 a371e86f-e733-173e-99d9-05ed6e8b6c31 12 2d13bc18-485e-2300-814f-65f334d92320 13 6f44a50d-ed13-8d9a-ae91-f2a99899452a 14 f5dd2d62-b88d-1879-9d18-9841a2dcf549 15 ae5abf41-8987-0af0-949b-1a1d2d593742 16 c2831ac4-4a00-0438-9ae1-f0694bb46839 17 2f63f862-fc88-3341-b9bc-296a0a9ef56f 18 21fd94b8-a194-7dbf-8300-0da45d659379 19 d7532bcd-e79c-6b59-bd5b-0731b498ff23 20 0c6fc931-6121-4875-99b9-e921738439c5 21 0cb897c2-f955-2a59-8e0c-9c0ab2b78d5f 22 4ec8a32f-83e8-2019-a5fe-9ef3fe332618 23 dc31248f-ecd8-7b69-aaad-7c69a8c2c95c 24 1ee017fc-68b2-542d-a37d-642df9af7d1f 25 4a90c8e7-54bc-5849-b25f-54e63a82d8db
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
8015588184128100376422755. Exactly this sequence comes out ofnew Random(703).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. This post is draw 11 of Run 18 (seed 6,051,781):
new Random(6051781), Next(8,64) per post. The RNG predicts N = 25; the post has N = 25 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-07-27 19:15–19:16). - Conclusion. Filler. The content is fully explained by the two RNGs.