201209212230 10a4u2

explained decrypted filler

3DES(name+title) ECB, 24 GUIDs, seed 761

Metadata

Post ID: 10a4u2
Title: 201209212230 → 2012-09-21 22:30 on A858's clock
Posted (UTC): 2012-09-22 02:30:08
Timezone: UTC−4 · title 22:30 against posted 02:30 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,552 hex characters · 776 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209212230) = 651f93f953747b6567e1e93f480505a0 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 24
Filler GUID seed: new Random(761).Next(9) ✓ verified
Run: Run 33 (seed 1,220,410,968) (seed)
Draw: 9 · predicted N = 24 ✓
Machine boot: 2012-09-07 21:49–21:59 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

54FAB5C1C94DBFA3 F7F1D3A0E05FB4E3 F30C06FDA033C954 0CC72B9DB9A20A7B C5775AB4CF5252E4 96C4D6DBF40537AF E17B287D6CC82480 6C70109A0D88156D 07334FC1E457A8ED B8F0649C353C2F6D B622664CEFD78AB1 EC6830D84986D081 237F33B02C6B17EC 6DDF8B355D5E3A65 AD52FA7EF520BEC4 B41D238DFAEBB7DE 687C2964B22F6D2F 3E282FD7B2CB8AF5 7CCB70C7ACF53BAC DDAD2E1AFE2ADD74 544BD09BDB8B9215 D39828E7D083D573 C69C87CB0DCB8B02 7D6847F0A373217B 7281DFBC963EAEBD F327FEA7D333B440 681F3C2E7D2292E7 8DF3730E3E39CF2C DA4C347ABD3B8FBE 354EDD0DEE47DEDF A9299B0A7B0624D0 54B2F561473A3929 0BF16118E6651CB3 97D1E892B473311B 59FD65EFEE3B4DF6 96E4FC552C9310B8 89113B7DD6F1ED97 F8AFC6C444CA69C2 D67B53283478CDA8 3436E0D6EFA91893 0A573648DF54EA13 8EC1B3D7D5F47A0F 24F4400FE30625C6 F28CAA58F718F531 AD7B1E9F29281F1C DC12A847694802DD AECFCDB78FBF5A4C 7A3EAADF1F07D64B 5082EFA8B5495D4E 7EE104F303C1A6EC 8C6505BBAA34797F 3E6BFE8B0DDC3860 7E0C2292E60FC2E1 6D47BC642AE41EF3 A86B5A9FAB8AEAA6 47A5161A95074ACD 549DF174C82EE59B B6A41D3203627AF5 86E97257F78E6951 D89C5D9928B0D7D8 153EC4260E41BAD9 328B0FAE5215129E D45E4CE9E191DEB3 25C16F930CE62EDB 0EFAE06A9F1F7CFF 80A23FD51361D3A7 C21678C477D9FF15 C973201BBB7C9550 9A5529E7EE4D12FC FDA42F5F1736DFC3 509E2BC87C134736 51C3EC9E8031002D 1F7BBD443594D995 36110F08B5B34B9F BACF925CD6DBDF66 9B14AE1C3EF15725 C17F2CD222E01BD8 545738FA6DC7902C 1B78909CC7C10FB2 CAC00B775F8C06F7 C0F37C10791FABE2 DBF3BB5AA60460D0 59FFEDC5F02DE020 1BA66B1781171C46 A94D909B505BB093 28E81EFA185DA004 C81854D6A43A0E5E DB6BA4CC9413F1DC 3B1EA5B87E0D40F8 5C3A3EA7E7F753E8 F348706E3C12A3CC 7B30E430FAE11DAC DA5EBF00F3AFEA38 62BC6136D422584C 657AD7BE72EBC78D 7A497B4D29A8A2D8 53629D1413E8E1B2

Read the ciphertext. Strip whitespace: 1,552 hex characters = 776 bytes = 97 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209212230 (name+title). Key = MD5(password) = 651f93f953747b6567e1e93f480505a0, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 24 GUIDs as hex (shown below).

Decrypted: GUID list

  1 bb78dda7-e559-29b6-b1a2-a06c1967734b
  2 5198ab55-9ae4-0fcd-83d7-2daaccbb234a
  3 815c0f25-4e08-651a-ac0f-2075eaff18fb
  4 10543362-412f-8618-b090-b6f721abca0f
  5 e4ca9bfc-ddbf-7312-8cd4-14acb2b4c28d
  6 7ce4e0f9-38c9-56b1-afc3-cbf51c419a78
  7 8669b8d0-c085-73cd-a035-7b2a73c57312
  8 8e0c3999-f4b8-2a89-9293-1ecc8f324a67
  9 2384d19e-8666-1265-bc0b-3decb774ff8b
 10 f6d572c7-16fd-8e63-af0c-173aec4f4def
 11 1a966828-57e7-8733-b18b-cfddbaf58d39
 12 3689b055-0d9c-5014-be10-36ba41e8ab58
 13 cae27a26-b29c-79fc-abef-5bd9fdab66b5
 14 d7b298a4-0e93-391c-9f9a-ee1efc8353e4
 15 279fadf5-e49f-5af6-a059-4fd9ff15eefe
 16 e5fd8d0c-7d40-2a9a-9eb4-269a28bd253a
 17 85045f7b-70a3-6f75-9473-af16a08711fc
 18 cc30c227-34ce-705e-9864-3781b19b4080
 19 7620086c-4dfa-227a-841b-d8f135271c16
 20 47809339-4cf4-8099-90fe-ff61c730de5a
 21 9e79bb9b-a8a7-8627-8ef4-5b1a684466d9
 22 5a5bbe94-9919-4bb6-8fc1-6b4ce5b14cf1
 23 ad249c91-ae2e-5695-9b63-79384a454dd0
 24 51cda15f-31d5-70c0-94d1-2f86f6a685c3

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 206875721885735267288457. Exactly this sequence comes out of new Random(761).Next(9): the per-post millisecond seed of the mask generator. The other 30 hex digits of each GUID are Guid.NewGuid() output and carry no message.
Explain the count. This post is draw 9 of Run 33 (seed 1,220,410,968): new Random(1220410968), Next(8,64) per post. The RNG predicts N = 24; the post has N = 24 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-07 21:49–21:59).
Conclusion. Filler. The content is fully explained by the two RNGs.

Metadata

From the post to its content

As posted (encrypted)

Decrypted: GUID list

Explanation

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