201210082146 1167wl

explained decrypted filler

3DES(name+title) ECB, 16 GUIDs, seed 317

Metadata

Post ID: 1167wl
Title: 201210082146 → 2012-10-08 21:46 on A858's clock
Posted (UTC): 2012-10-09 01:46:40
Timezone: UTC−4 · title 21:46 against posted 01:46 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,040 hex characters · 520 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210082146) = b402fae5dc9091d3f55fd28bd6434111 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(317).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 485 · predicted N = 16 ✓
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: 0 · 1
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210082146 (name+title). Key = MD5(password) = b402fae5dc9091d3f55fd28bd6434111, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 2b767e50-f09e-3de9-b49d-e5424c96d139
  2 56312ca9-905a-772b-a482-0597b19af3ef
  3 22082ba2-8bad-3760-bcfd-c1c286b5590f
  4 851df138-48f5-1bdf-9207-1ff11b822e02
  5 86234efe-4312-28eb-9e7d-ccf7ad4c2521
  6 96fb3309-cda9-561a-80f2-74c2e841b290
  7 11baf9f1-d81e-8101-9241-d66ea68f8e1e
  8 ee4a910a-40bf-45bc-b1d3-0acf3ba1f976
  9 2b77d2a4-f414-1c76-ac1f-96ed9ccb607d
 10 bb9c79e7-ebdd-19af-b709-9c444eff5add
 11 c8623c32-1e43-7cc9-ae80-7d247fce3e93
 12 4b6663b7-157d-851d-b847-e6789263636f
 13 f04fad50-8ffa-4d87-ae11-e70110f176fb
 14 96acfb88-3e54-391f-8742-aa3287ea33b3
 15 cb46403a-1fcc-78cc-9037-6c3dbfe30665
 16 a54ba108-3a5f-0c20-bca5-b8011ba5482f

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3731258411784370. Exactly this sequence comes out of new Random(317).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 485 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 16; the post has N = 16 ✓. 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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