201210021920 10ue4x

explained decrypted filler

3DES(name+title) ECB, 21 GUIDs, seed 735

Metadata

Post ID: 10ue4x
Title: 201210021920 → 2012-10-02 19:20 on A858's clock
Posted (UTC): 2012-10-02 23:20:40
Timezone: UTC−4 · title 19:20 against posted 23:20 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,360 hex characters · 680 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210021920) = a2d6e0780b34fcabd7248e0aa2cb009d (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 21
Filler GUID seed: new Random(735).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 46 · predicted N = 21 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

30D8CF40F98FCBAA 821745E185006AFB 29DDA98EA667C72F 61F1359B58E6EED9 B37A8011E8B164A1 082071BBB9E9EE99 0FA54B2C0ECEB2FE F3560F4A59A51915 1D565E7732518375 679E14BFFF84E6F2 658269832263B0CF 5DC5F61FFA1F6F04 9B3239637176FB37 2886446D1BEAE3A4 60E97F745A86DBBF 1532689EAF385EFA DD7DC2E4955DF57B A22AA9585D3EF27F 263D97F2BF6234EF AF6F76E0E6256E4B C2424148018F4363 48FE405299D47628 5EFA5C666D61542C 383C23B11A06C817 F3FC1A37A1157D2E 521B49D49F6B14B5 B5530F61343731CA FF0066AF59BCD81A D473FC5DB182823D 91BE5032D8E43491 EC98BEBCBF3DE8B7 360CF00457DA7674 7FE4F8C2C1319289 5608057A937B282B EDFE464E5E94ECFE 098A5C4292C588E0 D2F1D609CB045ABF 1CDA4C4B4A799307 C1795045E4470C11 0718668B54AA0F8F CDA789D32695EFFC 9DBE4E6B64997A2D 571BE8CF35589071 09AD1BD005483C01 5618C429E453E6F5 166F72E76D0DC53D EC95C98031CE8B06 4EDF1CD54FB95A5C 1B48D7CD6C79CEA6 1882FFBD8349B2C2 8E707558D48027DC 96C3075C0A3A5B32 D1E951371670553A 217B1AFCF5D5F8B5 437DC3A79CD55288 CFFE382405703A37 AF5D434B1084E67D 374B61641B984B5E D07B315218B59873 9284E1A29015AABC 03592B6E7C593250 2CFB0BF0E389AFA7 6C73875A4327D1EC 19887D236DAC8FF7 77DFBD16E00F78A5 ED6E7D37E39976CF 59B85993A928C112 97D4005E06D7F795 379836AF55521E72 70B5023E67FE5E00 5C1CC3EBE03D81E0 1F37F7B28F744223 43E452715B28E291 06A24825BC1CB73A A56DBC07F9168C77 1DE964E23919EE4A 2A8049575D5DC808 033F2DFC4F2EF962 B9962739A10BD736 BA3B6B556264F30B 81C0822B5CF83344 BA0CF1F8405312D5 32E8A5FECDF6621B F12E7159FF7C2517 8DCC4BB8051E7BD7

Read the ciphertext. Strip whitespace: 1,360 hex characters = 680 bytes = 85 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210021920 (name+title). Key = MD5(password) = a2d6e0780b34fcabd7248e0aa2cb009d, 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 1c37e1d5-cdb5-6371-9db3-99f57cd4cd94
  2 30db536b-4de7-4cc5-9552-94dd8b74c52c
  3 dc47a913-289e-4140-a4cc-8142e2c60cbf
  4 f873f5fb-444b-32a8-be4a-f3f2e37e32f1
  5 f087a8fd-52b1-0c95-9c32-28f7ebd9fc12
  6 b4862cd6-aeb7-7d2e-bca6-91f8bbf3a662
  7 c1b4d638-b516-239a-a458-ef50c28ac5e2
  8 da7f7a79-7bfe-1286-9af9-7dd3262f206a
  9 39d6b6bd-d613-85ce-a5c2-538baca7ac25
 10 8cb5275e-98da-2457-b60d-e6f080020bab
 11 fa7e79ad-87e2-7667-9279-0a21fd7c982c
 12 5ae04ba6-01a1-2187-961c-42e6bf58fb3a
 13 292e683c-0500-8669-a69a-b7beadb3fc81
 14 6dad465b-a8ab-7175-aae2-ffb24fa6e601
 15 daee5c91-7d62-4217-b3f7-1b4ff7c7e086
 16 ddec9587-610a-0f81-95fa-50365ecb0e49
 17 cffc23c1-5dce-77b4-8b7b-7b533d1d821b
 18 c588929e-be60-6649-8694-d3767b257d39
 19 9ed61be3-2109-5087-9558-49bb3c1d5158
 20 a181d13d-d460-8c18-aa0b-eb31ae1fc23d
 21 37e3ba49-c9ab-41af-90e1-4bb1c150d048

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 644307218272874076584. Exactly this sequence comes out of new Random(735).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 46 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) 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 2012-09-22 10:16–10:36).
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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