201206261618 vnmdq
explained decrypted filler
3DES(name) ECB, 21 GUIDs, seed 251
From the post to its content
As posted (encrypted)
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
- Read the ciphertext. Strip whitespace: 1,360 hex characters = 680 bytes = 85 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 21 GUIDs as hex (shown below).
Decrypted: GUID list
1 88d50791-5a22-7d8e-a810-3603054b9115 2 caf74240-2c9e-4b03-935f-258dafc89380 3 b47e0faf-bb1b-1d89-b57e-e10f51bbff85 4 90f0d61c-a221-171d-8b71-7cb0fba37638 5 374dabc7-5445-4fde-81f5-903d601d8d71 6 a14f692b-8026-8b11-86db-e48870418fb1 7 3f341ee5-2818-3ab4-b943-684d61cb8086 8 78b6e20f-087a-3d7a-b19b-0d800ad26141 9 8ca96357-e497-029a-afed-b813730a3931 10 80bc77cd-a0be-7361-87c4-91d477ac8a3c 11 facde58d-ae3c-113f-8386-5e077b39af75 12 c6eb018c-29d9-35d4-ba22-851625d0f65e 13 ff934f4a-f88a-1da3-8ea8-edb84594573a 14 a6d47db7-1cb6-0a2a-b5db-55b79032745a 15 e2306102-c285-6a85-bb42-028ffe47c67c 16 a3913c10-c210-7c3b-aeda-3de66feaa72f 17 24d4354d-b243-3448-9154-b7adca0d7573 18 185577a9-37a8-51e3-ba31-85b13a5a1ec4 19 1cfd4bf5-68fc-456a-9710-01731e9bffb3 20 278b8158-3de8-47b8-be65-c170cd4d1448 21 36888b37-e2db-1ef8-98e2-558723331250
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
741148330713106735441. Exactly this sequence comes out ofnew Random(251).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 2 of Run 6 (seed 652,173,660):
new Random(652173660), Next(8,24) per post. The RNG predicts N = 21; the post has N = 21 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 19:06–19:16). - Conclusion. Filler. The content is fully explained by the two RNGs.