201210080045 114g9y

explained decrypted filler

3DES(name+title) ECB, 14 GUIDs, seed 846

Metadata

Post ID: 114g9y
Title: 201210080045 → 2012-10-08 00:45 on A858's clock
Posted (UTC): 2012-10-08 04:45:42
Timezone: UTC−4 · title 00:45 against posted 04:45 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(A858DE45F56D9BC9201210080045) = fbd7c9138480986cfcfc1c1d2067704d (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 14
Filler GUID seed: new Random(846).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 422 · 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: 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: 912 hex characters = 456 bytes = 57 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210080045 (name+title). Key = MD5(password) = fbd7c9138480986cfcfc1c1d2067704d, 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 4d571754-7de0-6cfe-b602-e6d06d38aa08
  2 1d3b70b1-e94a-0a72-86e5-9c4f70237692
  3 836cb713-b260-1def-87d4-0347e958470b
  4 279d0091-1232-114c-ad82-b9ce906bba79
  5 6e7ac902-e3ac-17cc-85bf-59dda0c0fc7a
  6 b20edd6e-4784-77c8-856f-a1659b55d85a
  7 e2fd8dc4-6920-81cf-b07c-b080cc91f5a7
  8 ac74509e-173e-73d8-b2ef-0f9afdd4d0dc
  9 72bab0d4-2913-5d21-a36f-454731a0839f
 10 47567be5-ac56-2564-b238-1fe21b5c557b
 11 90e4b715-f5cc-5163-ab9b-4f1a21aa6efd
 12 d6e58384-bd84-82dc-a723-a71285d644e4
 13 496ba498-67f9-1e2f-b6d1-f4395d8d68d8
 14 fedf71ea-d417-5048-ba10-c07a928afb40

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 60111787525815. Exactly this sequence comes out of new Random(846).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 422 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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