201210052103 110t0i

explained decrypted filler

seed 416

Metadata

Post ID: 110t0i
Title: 201210052103 → 2012-10-05 21:03 on A858's clock
Posted (UTC): 2012-10-06 01:03:41
Timezone: UTC−4 · title 21:03 against posted 01:03 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 912 hex characters · 456 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210052103) = 592900502e0a3714a5ed38030542350e (name+title)
GUIDs: 14
Filler GUID seed: new Random(416).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 267 · predicted N = 14 ✓
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: 4 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

5E1C5C58D9A755B6 C5CB32B3FC27E29E 485A53A6422B86E9 176464C72316CF6E B05CA49F06874FA8 61CFBCA77D28D551 8236962005ADBDDB C4E8360616108A8C D26BED57CDD3B9BE A8117DABA075F2D2 8735967C0C50AD40 06FA4F0AC4EBFCA0 5F99983D9BBB186D 94742E454618950F 4AD44E13F03A05E1 A3F721BE128ED9FC 4318636FC9293BDF 5194E39D8CEEAC85 97C8D620F0A2746D 016EC2677C320BF4 A50CBADB697FA743 6FA5886D79727E9A 0DDC718E0A64E9D4 2630DAD8A94E76B5 E5093BFCB495A228 B500F21B03F5BA82 6B2528FD0AEA7FBF E0694562F82CC365 483EA3AEFC0C39E9 032CDCD08E6B9B14 9596E87434C4EEF2 2C3A3B725C77F7C0 DE57E72D908397A2 13F2C884F2A1DD25 A507815BA5F567B4 941827CE8FD1198D 9AD2FF26311DF23C A63F25FB4F179FBB 618AFD5C3AF3509E 910955EF8B446626 9A1C7E8AD507522E E07D8D155A105DB9 24F7F9E6E819A46E FE38AC5620B0BF1B 1A49CB5E89637963 182D32A0084C9CBB 2C34F4D45C2107D9 8E4228FEAA3DCFEA C79A6403D0F5E203 264E2DE04DA7726F C145D466F4BB4CDF 8437746BDE32EE0C 940F072ABE9DF17C 48D52C85141BCEDA E6C34B7FE99C67AC 78418B04BC52EBB7 B7DD352819B6C776

Read the ciphertext. Strip whitespace: 912 hex characters = 456 bytes = 57 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210052103 (name+title). Key = MD5(password) = 592900502e0a3714a5ed38030542350e, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 14 GUIDs as hex (shown below).

Decrypted: GUID list

  1 fd47ae1a-9cb0-00a2-99ad-11b8004da540
  2 16039e16-0687-7b39-8d28-6579b3243cba
  3 5d4d98a4-3d4f-4df7-8363-0955d5a8994e
  4 48663035-b1ba-344d-9395-b1d126ec9f0d
  5 80412c6c-22fb-0a28-b1b3-2e9758646da3
  6 02e80ea3-da92-0cf8-a438-46107c81ff7d
  7 61a6ff4d-1f32-20a0-8367-eb39aaac1e25
  8 9b92f597-2767-1436-965d-22d0991c4119
  9 af83c196-869b-34ba-b0c9-2d7bb74ce459
 10 2b2d72e3-a1eb-6d5f-bbd0-44d50e5af931
 11 c4018350-fad7-6f8b-a03e-725da9854c39
 12 d330ea09-56e3-22ad-a864-f8d8a6adbad6
 13 78f5f1f0-3c3b-5176-a462-89c6663f2211
 14 955bd4c7-103d-8dd0-beb1-6a0535354c6d

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 07430021366258. Exactly this sequence comes out of new Random(416).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 267 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 14; the post has N = 14 ✓. 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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