201207071336 w5yxb

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 392

Metadata

Post ID: w5yxb
Title: 201207071336 → 2012-07-07 13:36 on A858's clock
Posted (UTC): 2012-07-07 04:34:13
Timezone: UTC+9 · title 13:36 against posted 04:34 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(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(392).Next(9) ✓ verified
Run: Run 11 (seed 37,057,156) (seed)
Draw: 31 · predicted N = 16 ✓
Machine boot: 2012-07-05 09:16–10:46 (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: namerun: 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 = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, 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 365174d4-cea6-4ff7-bed5-9df193870a31
  2 1bbcd784-f6e9-787d-a010-5dce48f62f09
  3 d238353f-f1bb-6bbf-8411-c766575ec770
  4 36d9f910-1dec-2845-a63e-61610df55d03
  5 c47dde72-4317-10a3-b435-46aa313de7f8
  6 37dd5945-66a8-1b7e-8870-5e4a0b1b1313
  7 64084361-dba5-455c-bd73-f5e93d6b43b4
  8 f4f03f47-6cd8-0662-98fa-bb7a06a9c1f3
  9 43e9a478-c2be-4352-90e7-b6bf823a4c32
 10 ae151ff8-a707-7ccc-b8cb-bdda2c3c6e4d
 11 bef35bcc-c3cd-0227-8399-ab955c52b488
 12 ac568db0-26ac-4dd4-b839-ebdeed26846f
 13 9dd78776-22e8-1b68-92de-9fb1bef8d042
 14 263e78d9-d4bf-3a86-8999-04374c5972e7
 15 f3d4cee8-02f0-3342-9f0a-0892a9f8e4d0
 16 63c88a80-df6f-758c-a349-fb0be8b7f629

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 4762114047041337. Exactly this sequence comes out of new Random(392).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 31 of Run 11 (seed 37,057,156): new Random(37057156), 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 2012-07-05 09:16–10:46).
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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