201210071745 113t05

explained decrypted filler

seed 968

Metadata

Post ID: 113t05
Title: 201210071745 → 2012-10-07 17:45 on A858's clock
Posted (UTC): 2012-10-07 21:45:27
Timezone: UTC−4 · title 17:45 against posted 21:45 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,424 hex characters · 712 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210071745) = f53008ce50ff323d138367374e22035e (name+title)
GUIDs: 22
Filler GUID seed: new Random(968).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 401 · predicted N = 22 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

58082AB4AF6E0113 0AA1B4ECC8069498 31ADBDF8EA79E725 FFCF8724525E093A 6F44FC3D2E2C76DD 8B0B01A7EC7A1EF5 E35D04040134E0ED 982395A86EAED472 9EAD414526E4C462 9A5B9A5B8F2D2482 FFABE0E2D3CA5234 AC0F3465FA84F950 768C21F2F5DE53B4 0EF154DFB550106C 416D9158256708A3 152147D8152C2845 959D3731FEC5A1C7 E04715D70F57DBDB CE3298A0E5DE9BC5 5E60C756849DBE8F 45215CC21429AFCB 4824785C3071C979 B59DE983BCBBAE57 B64110B00ED85215 29D538817A524DC7 24CE2D86BC27267E 089D0A15773104E3 A23E3722900F47ED 86A8673AA4AD3CCB 7AD38B088BE2AE73 AB2B3759349FB875 F65F278248D8539F BF756685EDA36D76 ABBEE460533A5B0D 291589D040425594 AFE1888004416C44 B4DFE186A5ADDB22 21C5BE09607190D1 9133559D18F74731 30B392B389370062 D6DD60E14187EB60 D41BBD69F30E1673 CA80CB5EEF21C973 15A04C4079D9220C 91D4957F4EAA5871 FC975DE53ADD80F0 9A8ED19697DA2DB6 4B27119C0EFD60EF C18C6F0C927F5819 0D14F54AAC351590 A9D505459B700B23 E4A73C15FCAAB5D2 61ED5153784D3531 42FBEA0F07DB83C3 7DBF74A12B07E967 213BE412E8246A09 559BACA6867F310B 363E1CFB469D2CFD 2E75C72B200444F1 8F028A0A1BFEB9F9 6C48F99E7720E97D 27E67E99506DA96C 4613CDB92B095BC2 F00DD6A3BA7B207E A3428349EE64C51B CF73447853DDFDA0 835F09A03C1DE359 2EACD53D25CAF169 C409C70D654A8AFE E32414ACFEF9CE55 141811F6D4692729 357CB1A56014B2EA 86F508A8F57202B5 A1531824AB6CDC0C DEC557139419AAF1 2DB35CCBE473A602 47CCC71568125DC2 E43B225F97509A66 0D618B50DBB01E7F 47228A3227C127D3 33B3F87EE567E7CA 7730AE3A0265E792 EDE192940F492E2F CC51AF9542BA660A 0DF24B8F5F7B2A4C 618F3ED7BD9C605B 7CAD109A78CA46D2 614991C713A42CFC 73E61B999089449F

Read the ciphertext. Strip whitespace: 1,424 hex characters = 712 bytes = 89 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210071745 (name+title). Key = MD5(password) = f53008ce50ff323d138367374e22035e, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 22 GUIDs as hex (shown below).

Decrypted: GUID list

  1 67edfcfb-02a9-3b9d-a2ab-841d1da90c40
  2 dca574ca-cf39-7425-b9a3-06a1e20d1c15
  3 a639925e-c4ed-35b4-8945-822e0cd2e2a1
  4 ba63add0-e14d-17ce-8f58-bdcdb551ea15
  5 7c3e9d24-7e8f-2e2f-83a6-f5c67a26bcb9
  6 609e3e54-a332-4afe-9c0d-d60ba94ee4d1
  7 11904f8f-2364-5dfc-8da4-778498ef8786
  8 e7574adb-6b74-0169-bfcd-0763364059ff
  9 42b22bf3-c101-6f58-b074-2b75d0aa25d4
 10 c6b0fa7f-cf78-24f2-b235-571a1d808791
 11 a00ac341-00dd-4428-b1dd-c37ed7fe3cca
 12 0e525b59-235b-16aa-9af4-b86502f90bf3
 13 53a54d29-4650-05c5-b3ee-a44812520d05
 14 8a4d9860-c882-0d4e-9afa-f11836a832fe
 15 9e0b23dc-fbf4-4dc0-a3d9-ac68fc67f605
 16 61cc53b6-e94c-545f-86c2-ab4f04dfc6e5
 17 ba1597cf-fb50-6b56-b77a-2f9a266ecbc4
 18 f82555e7-6682-1a0e-a48d-8852d70f5049
 19 ec950a78-e7f7-7f10-88f8-ac375cb6d747
 20 663d338a-2677-1537-acad-3e8372a41f02
 21 2af61c19-2d40-36b9-b8dc-9b01122c949d
 22 0791be88-f24d-3fa3-9d1d-70740cc8eb2a

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3731245062410045617133. Exactly this sequence comes out of new Random(968).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 401 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 22; the post has N = 22 ✓. 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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