201210082306 116del

explained decrypted filler

3DES(name+title) ECB, 8 GUIDs, seed 489

Metadata

Post ID: 116del
Title: 201210082306 → 2012-10-08 23:06 on A858's clock
Posted (UTC): 2012-10-09 03:06:43
Timezone: UTC−4 · title 23:06 against posted 03:06 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 528 hex characters · 264 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210082306) = aa233a364b70ec337dff37fc211a2efe (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 8
Filler GUID seed: new Random(489).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 489 · predicted N = 8 ✓
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: 528 hex characters = 264 bytes = 33 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210082306 (name+title). Key = MD5(password) = aa233a364b70ec337dff37fc211a2efe, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 8 GUIDs as hex (shown below).

Decrypted: GUID list

  1 3e093423-c1ee-1f36-8092-2757d27d066e
  2 aa4f37ba-4ac5-21d7-9ba0-8c1e9000e40b
  3 455512fc-94ef-5253-97cd-5fbf84a3c786
  4 d3f912e8-7e8b-8d86-bb10-5ac116fd9304
  5 61d8636a-77d8-8723-81f5-9ac97495973b
  6 bc4289dd-85c8-81df-b139-c93723d8ffe9
  7 4efce06b-9b58-007c-9192-34902eb16117
  8 9191b1ad-c343-60f7-b1eb-b47d78407ec2

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 12588806. Exactly this sequence comes out of new Random(489).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 489 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 8; the post has N = 8 ✓. 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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