201210080005 114e6q

explained decrypted filler

3DES(name+title) ECB, 14 GUIDs, seed 186

Metadata

Post ID: 114e6q
Title: 201210080005 → 2012-10-08 00:05 on A858's clock
Posted (UTC): 2012-10-08 04:05:40
Timezone: UTC−4 · title 00:05 against posted 04:05 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 912 hex characters · 456 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210080005) = 88ab7ca4aa5d06221abc6fabe3d29eb4 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 14
Filler GUID seed: new Random(186).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 420 · predicted N = 14 ✓
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: 912 hex characters = 456 bytes = 57 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210080005 (name+title). Key = MD5(password) = 88ab7ca4aa5d06221abc6fabe3d29eb4, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 14 GUIDs as hex (shown below).

Decrypted: GUID list

  1 9f1fe204-a4bf-8b3b-8f34-ec6b78a8bf95
  2 abd0d22e-5a5a-39f6-89ae-c1e85225b3b9
  3 7ffaba9a-2dc4-7fb1-87ff-1369f32f83d3
  4 f3f70422-ff6e-28b3-ad3b-4f702e6f6bd6
  5 30b541fb-3737-116f-b586-69fa944497f8
  6 04d485bd-afcc-03da-9555-4f32e691f3d5
  7 c604b75b-bb1c-2378-8cdb-cf2167b8a04e
  8 e1a3e2a3-cf07-6b4e-b677-53ed77839a16
  9 33eaf629-1633-82ac-96ad-f9b466e8d702
 10 0c5dbaf3-f0c9-743b-8761-6b82da180ac2
 11 d4eaed98-04a7-2942-96d8-cb23df573434
 12 7588c140-68e8-6345-bb5a-305e17753637
 13 47bc1a0e-1ddc-4df3-9b80-8591f4c5dc2b
 14 d4bb6ef0-5ea2-26c5-a533-de74b18889fa

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 83721026872642. Exactly this sequence comes out of new Random(186).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 420 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 14; the post has N = 14 ✓. 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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