201210102300 1192gr

explained decrypted filler

3DES(name+title) ECB, 20 GUIDs, seed 109

Metadata

Post ID: 1192gr
Title: 201210102300 → 2012-10-10 23:00 on A858's clock
Posted (UTC): 2012-10-10 14:00:31
Timezone: UTC+9 · title 23:00 against posted 14:00 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210102300) = 96aecb512f5abaf163ab2112eb3fc4dc (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(109).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 528 · predicted N = 20 ✓
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: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210102300 (name+title). Key = MD5(password) = 96aecb512f5abaf163ab2112eb3fc4dc, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 b652b386-3f1e-6b1c-bce8-908f7db5b6fa
  2 80c442cf-168e-7861-8b7d-6c4b9cb75210
  3 6d39378d-bb4f-805d-a716-df9edce7a0e3
  4 d995633c-186f-772c-a35c-1fddc260bafd
  5 e8cc22c8-f4d2-34c2-a8d7-8c1ca924b752
  6 ceb5625f-418b-7f72-9f40-c085c5604c9a
  7 72c28ce8-27fb-6ceb-a87e-13d59ffdd25f
  8 10e862b4-1ba9-15f3-aefb-23fbb83081a8
  9 bf5d4f64-dafe-4948-ac9e-f3c9b403ff62
 10 b340767b-ba46-44f8-aacf-32a1fa11adba
 11 5027db48-70c8-5643-94bb-00dda18fe6b6
 12 3e18c338-dd5b-51b7-b9c7-345245c0b42f
 13 8f4676be-63c4-5f59-b7b2-730b24247808
 14 fc6900a7-4d29-17a1-b4c3-171c871434f7
 15 6036cdff-6b35-226c-a857-b88439a3a586
 16 8c548787-ba2f-0aa7-a1c1-97320b066016
 17 e1f3fd35-b052-68cb-84e4-b2a560d89222
 18 c5ad1b8b-cf1d-5a2c-8f09-faf766610eeb
 19 e4be8ba0-65b9-565e-a246-2969c5004c0e
 20 1c208efb-8727-48cc-b47a-0dc7309a7600

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 67873761445551206554. Exactly this sequence comes out of new Random(109).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 528 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 20; the post has N = 20 ✓. 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