201210051123 10zuwf

explained decrypted filler

3DES(name+title) ECB, 12 GUIDs, seed 38

Metadata

Post ID: 10zuwf
Title: 201210051123 → 2012-10-05 11:23 on A858's clock
Posted (UTC): 2012-10-05 15:23:16
Timezone: UTC−4 · title 11:23 against posted 15:23 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(A858DE45F56D9BC9201210051123) = 9eca97caf41af1672b0113cf938bc273 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 12
Filler GUID seed: new Random(38).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 238 · 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: 1 · 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 = A858DE45F56D9BC9201210051123 (name+title). Key = MD5(password) = 9eca97caf41af1672b0113cf938bc273, 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 0b830ca9-b95d-5dd5-a5e5-2db75a20e691
  2 6dceb889-232b-87d4-984a-a273f0bca118
  3 a499e9c3-36bf-2e87-8873-fd7b13d6f96c
  4 377a57ea-dcd5-6725-8c6a-9166cdca76f8
  5 8a8b44b3-41e4-32cd-a5d0-4310b89b6e3d
  6 624c22d6-f661-6663-bbbe-c9f1120ea44f
  7 ed3e2f2e-ac28-8e35-9d01-fce97c7e1d81
  8 32ad8828-e5e0-4a4c-8f29-884c0d09be2b
  9 e971b557-11bd-6433-8b6c-f31ab86b3e55
 10 97026e6e-c4b0-27ec-b097-5bd9bf1cc5e7
 11 98707e7b-854a-20ed-af2b-deb7a694357b
 12 59159400-70d7-144b-a5a0-737d13be0b65

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 582636846221. Exactly this sequence comes out of new Random(38).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 238 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

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