201210050743 10zl84

explained decrypted filler

3DES(name+title) ECB, 11 GUIDs, seed 805

Metadata

Post ID: 10zl84
Title: 201210050743 → 2012-10-05 07:43 on A858's clock
Posted (UTC): 2012-10-05 11:43:09
Timezone: UTC−4 · title 07:43 against posted 11:43 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 720 hex characters · 360 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210050743) = cca9680a9bc15bcce37cc2c486e88029 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 11
Filler GUID seed: new Random(805).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 227 · predicted N = 11 ✓
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: 5 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

9CE4D8BC94A20AAD 15299539382DD2F3 FE826A0B8CA479C6 6A7FC6132E58643E 6E933F77F5193DB4 BD823A8E1CBA0F6F EE0658BDC4598EA7 2CA3D950CEF0BAEF 75FF97CFFA118E83 8262D52D4E9BB984 A96E3BC68F4B185E 7D698E69E6C8ADD1 60692C1804D14337 19ED9524D6B9D3F3 C9621ABF0D653DE2 BAD4FD7C5616B8F3 436372CB220F9E6E 196C018DC48B29A4 DC3A2A66CFD382BB A3E3E8CF7340DF85 2AA16BA0130052C1 DD5B4AC43CB31DC3 403D96362933C3AA ACC6C237A8A68CF3 4DB3B97E75222ACB DC38B46303493A55 31BE5E4EF27B3957 16C89781A9B6C428 C8A3E25265F95604 89C81F9329668E06 EBF24A32BFB7C555 4693C199A2DE30E8 3B620394EBA65E70 C2F03D2666852062 1422DE0D987B296D 0585D2B25F7B45CB 60B6D41076C225A8 9640A64145FB00C0 EB85BED9CDEE43B4 CE8221E15725EB47 023E048BA98E5209 3370747DCFD02ECB 4EDC8A73B031880E 22AD3AF281848642 ED85CFC632DBA20A

Read the ciphertext. Strip whitespace: 720 hex characters = 360 bytes = 45 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210050743 (name+title). Key = MD5(password) = cca9680a9bc15bcce37cc2c486e88029, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 11 GUIDs as hex (shown below).

Decrypted: GUID list

  1 769003cd-c826-222c-82af-2af92ba04b90
  2 1cb6d553-d6b3-0679-8e84-11f1dcfbe3a5
  3 5e6f9810-e5fd-4e98-b822-f2999e1da0ae
  4 83e254eb-afcf-3f74-9f88-ebf18b135ea3
  5 1d7b444a-5b92-5b16-b14f-d640ad2bb0df
  6 daace56e-f244-054f-a2d4-3b37d4cfaecc
  7 6a1a4ec8-eb15-5d84-98d3-baab55bfcb6d
  8 efc6d980-9595-265a-b197-ae4ea61172bc
  9 af98a805-a382-58a9-964e-ebb306991db7
 10 d8fbcf90-2942-11bb-a05b-475285f8fc59
 11 310e8393-d019-3790-b050-8008f1c75f0c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 20435052513. Exactly this sequence comes out of new Random(805).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 227 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 11; the post has N = 11 ✓. 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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