201210020440 10t3tm

explained decrypted filler

3DES(name+title) ECB, 18 GUIDs, seed 125

Metadata

Post ID: 10t3tm
Title: 201210020440 → 2012-10-02 04:40 on A858's clock
Posted (UTC): 2012-10-02 08:40:02
Timezone: UTC−4 · title 04:40 against posted 08:40 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,168 hex characters · 584 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210020440) = 6e74930eeedc982d59379c43166ac57f (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 18
Filler GUID seed: new Random(125).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 2 · predicted N = 18 ✓
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)

4286C48573A948BF 3E8B41217F3BFE78 8473BD5B61AB15BE B880A9E78F37C441 DCB04707B4BD726E B394FEB20B14E2C9 F8058F52F8BAB8A6 3F8C64F7309D6D89 ADFC924D06FAEDDC 4793A4703142531E 1850DFF9A7E017BC 1F4B92AB2898915A FF873033EA2DADE0 F43109ACE0042DB7 36B0E08170F40F25 9ECFB5624C77F409 B639192ECE0E458D 460CB734F4373BBB B41F1E889635F13B 7E2B19798A07CBCE 606AB5CA707C3B28 9C3257E69C4AC25E 2C8F0B46C0C9D787 083B0AB67BF1D11C 860F4C8A23EBFAE9 A286ABC1CC52BFE2 22E8CA2CD96B6B98 093FCD679B2C6F43 C9F2E515B79A429C C5F51449B62FEDE6 5D16D16F8F3A6879 C393A8C0D4EF0853 C3CF6DD48C5AAAE0 AC772E80D16D51C2 E87A06DD6D13C552 2C3660FD372EEF5A 864789DB1E78EA2C 2CA771CCB9ACA834 964DDEF3059FCB96 69C024F1BEC34987 AC2A9972D8B694C2 5CC24C3352B3D53D 31AC1A69EC20ED10 03967B91AE0CC5FF 99D6901590CB8089 DE50E034F4BCE744 65F5EA674B707C05 62AB6518F9B4FD71 EB15A1D809F957F6 D852346C2A985BCE 037CD228C4961F92 7872B0F71B158CCA AC3F905B4ABFB4F8 BEA6E11B55E2C4E3 6531641785414106 1FE3A4269CAFB4BE 31FA633C3C1EB9CB 24B6F68B7404FE7E F46334C2F233EAE7 0D1CB5EC75F854EA C2F343AEA955C291 DE697C3F7FC1A83A 61F066759F58DC47 E81C6D276D8B79F3 C53BFA0606289F03 45E0593D8F8DE59A EFF2AF82D1D681B5 F034D9F1249D6A2D 393D36E830C23978 7BD00D0D4A582654 44BCFFBBBFE2D847 1467BC45E6CCFB90 0A3FABEB79B505B0

Read the ciphertext. Strip whitespace: 1,168 hex characters = 584 bytes = 73 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210020440 (name+title). Key = MD5(password) = 6e74930eeedc982d59379c43166ac57f, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 18 GUIDs as hex (shown below).

Decrypted: GUID list

  1 af80a66f-23ef-0fbd-abc1-641663a582ca
  2 a8b6b40a-0c75-4f64-9df7-df94fe1c2249
  3 5d94d7e1-4564-160a-854f-2b797438afa1
  4 4732652f-fa5e-27c7-bb50-6be7f33a61e9
  5 a39cd648-f327-5cfe-a319-898a91429816
  6 20172f99-7563-7264-8b7c-b1c4dfe627fd
  7 1ea5c5aa-fcda-8626-bed4-c3bb6d64dc35
  8 8bd016c5-fe0b-1fd6-90fc-b514e5d3ffac
  9 6c79b604-69d8-3b25-a150-3ea967d788d0
 10 a482f576-a1d0-363f-8007-f86d1405f5fc
 11 2aae2979-db16-399a-9901-5ce025a3474d
 12 0c0c388a-eb96-080a-92d1-0e8b507f37d4
 13 9bb63de3-c684-5311-81aa-a0e83e8e64de
 14 f3080441-17c4-401d-9df1-c3bd6fa46f33
 15 d8dcc349-d7af-4d04-9811-502ba9050bd4
 16 c52d35be-4223-0c29-b9da-102969964248
 17 03f4c4de-ec5d-38cb-b80a-10a9b8628263
 18 d718b4ef-ef44-4cfb-883e-e2071922b3db

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 041257813330544034. Exactly this sequence comes out of new Random(125).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 2 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 18; the post has N = 18 ✓. 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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