201210030521 10v8cz

explained decrypted filler

3DES(name+title) ECB, 12 GUIDs, seed 429

Metadata

Post ID: 10v8cz
Title: 201210030521 → 2012-10-03 05:21 on A858's clock
Posted (UTC): 2012-10-03 09:21:08
Timezone: UTC−4 · title 05:21 against posted 09:21 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 784 hex characters · 392 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210030521) = f1cae1464148e66f5cb9e5f2e1d7d62a (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 12
Filler GUID seed: new Random(429).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 76 · predicted N = 12 ✓
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 · 0
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: 784 hex characters = 392 bytes = 49 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210030521 (name+title). Key = MD5(password) = f1cae1464148e66f5cb9e5f2e1d7d62a, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 12 GUIDs as hex (shown below).

Decrypted: GUID list

  1 a87cb273-161b-7960-a897-79fe41450949
  2 7b1f1db9-d0a7-63a9-8731-6d0aa17c2b80
  3 785ac9b7-84c5-51ed-ade1-b8d334b02cd6
  4 ab005d13-3ba8-1e01-b8b8-84ed96b4f575
  5 7498b8c4-1ffa-8460-9264-0ed1010824f2
  6 08c3b20a-1331-44f9-8bf7-f771aacca2f5
  7 6fb3f50a-54a3-1cb2-8a30-d1dbc5cbd5eb
  8 432f2627-b5e0-5077-9b97-f090e58cbf5b
  9 0c02b289-12e9-075c-ac66-05fd98db3bdc
 10 fea95a72-98f3-4d29-8c40-8338c86607b3
 11 bf32c0dc-5b68-338e-ad3c-9dbe5a6c53cd
 12 0122d820-5086-3375-a547-57eed08ebbe4

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 765184150433. Exactly this sequence comes out of new Random(429).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 76 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 12; the post has N = 12 ✓. 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

Related