201206261140 vn4kc
explained decrypted filler
3DES(name) ECB, 18 GUIDs, seed 510
From the post to its content
As posted (encrypted)
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
- Read the ciphertext. Strip whitespace: 1,168 hex characters = 584 bytes = 73 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 18 GUIDs as hex (shown below).
Decrypted: GUID list
1 a15ccdac-b75a-1510-9dfe-8cb79d98304e 2 d7b31929-fbd8-4b4f-953c-54c95b93f774 3 1e787d88-d7f6-2c33-ae9f-71006af93316 4 c8483920-015c-3d4c-8d92-bfa5e2a1cf02 5 02fdeb95-bfe8-4e32-9e74-a8b283a73ff6 6 5e6327a7-8bc0-2216-b492-1189017cd488 7 c66efb4b-671b-369d-aeae-edf66ed149f8 8 336f70ae-6d37-2170-868d-7be27d6d52cd 9 ddf47f4a-7f32-0825-b2ba-e7b2d1fbaaaa 10 da532628-61ca-3d97-bbaa-b8123407f882 11 a199fe5e-46ea-07f5-b81f-abfefcfead8a 12 59eb8be1-ac73-56ea-80cf-4d13bc73ac2e 13 9060ae98-094f-27e8-9b7c-ffbf43f54872 14 f83b2a12-81c4-7e6e-b6cc-049e58e3d8ce 15 01d9c4f5-ab80-8df4-834e-48d6e5de2253 16 6df33973-6909-4c19-aaf5-c8b92bf911ad 17 4428ff85-a5a3-2ef8-96f9-3d25bb8420f2 18 4b09a309-b031-1400-8048-c433c6b833b3
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
142342320305278421. Exactly this sequence comes out ofnew Random(510).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 45 of Run 3 (seed 1,063,142,882):
new Random(1063142882), Next(8,24) per post. The RNG predicts N = 18; the post has N = 18 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-06-14 10:25–10:26). - Conclusion. Filler. The content is fully explained by the two RNGs.