201210082246 116c46

explained decrypted filler

3DES(name+title) ECB, 14 GUIDs, seed 525

Metadata

Post ID: 116c46
Title: 201210082246 → 2012-10-08 22:46 on A858's clock
Posted (UTC): 2012-10-09 02:46:42
Timezone: UTC−4 · title 22:46 against posted 02:46 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(A858DE45F56D9BC9201210082246) = 599729115e883400441dcdf0557288b6 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 14
Filler GUID seed: new Random(525).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 488 · 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: 2 · 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 = A858DE45F56D9BC9201210082246 (name+title). Key = MD5(password) = 599729115e883400441dcdf0557288b6, 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 8fa8fc91-3a96-8c36-a1d1-ab522fd471d9
  2 3f4201a6-68fa-74b7-b90e-4ed8b62b27b8
  3 e64b9038-d2f6-6d27-9538-606e23140e5e
  4 58c3f01e-9d76-5263-b7a4-78d39cf960e7
  5 b05bfb16-88b7-2d1b-9699-a234b8b3a327
  6 b4f625dc-2da7-3619-b2a1-9881ec2a6f93
  7 c00a52b2-bc61-1883-804c-e20a90acb7a1
  8 21bb0835-85e1-711f-989f-843cf1578151
  9 4d7f12f2-6f8c-8eab-bef3-750480e3753d
 10 0381223a-8271-78de-9114-46a6348bda4a
 11 ce64eda1-78b1-0ad1-a314-d94a99b4778b
 12 5b7366f8-e6fd-36b8-9ee0-43cc52c3802d
 13 09b0362a-3de7-4bc7-b760-e4ce32351052
 14 9c45889a-e811-58ab-a64d-423c9ff8eee8

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 87652317870345. Exactly this sequence comes out of new Random(525).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 488 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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