201207052136 w3uq3
explained decrypted filler
3DES(name) ECB, 17 GUIDs, seed 73
From the post to its content
As posted (encrypted)
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
- Read the ciphertext. Strip whitespace: 1,104 hex characters = 552 bytes = 69 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 17 GUIDs as hex (shown below).
Decrypted: GUID list
1 cd6a92f6-cd00-7421-b927-0f808dccc0a4 2 473b5fb2-d64a-20fc-989d-60238dfe1075 3 ec332dbc-aefd-708e-8c37-ad8f84c910ae 4 2ecba3e6-453b-1321-8c80-bbe4fd971b6b 5 41350ff4-5599-1de6-9f89-bde412fa3721 6 d3392046-9d60-3470-85e0-21e845a0cfb2 7 f4826b30-0d2a-592b-b6cd-fd3d7136ac67 8 5a2bef3e-5ec0-0319-b6c9-1107c7fea4df 9 f43ff458-ea85-0581-993f-55b0df4d8af5 10 60474c27-b668-1e2f-aca8-98aa5bbce3af 11 7f9ebbaf-68b4-04b2-9f47-1c0a51efc278 12 2870d533-65a6-4883-ae3c-e7e2511ef10d 13 8cc3d67a-7585-75c0-8bc4-833f00b41043 14 5da1cf89-925f-46ca-aa05-c4737612ae59 15 b4da7808-8bc2-0337-9c27-458c400c96e9 16 99628bce-acc5-545c-8c10-f3a7f4ec890c 17 cce3e25b-35ca-4116-bb8d-284d28e08428
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
72711350010474054. Exactly this sequence comes out ofnew Random(73).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 9 of Run 12 (seed 36,542,234):
new Random(36542234), Next(8,64) per post. The RNG predicts N = 17; the post has N = 17 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-07-05 10:25–10:55). - Conclusion. Filler. The content is fully explained by the two RNGs.