201210082126 1166iw

explained decrypted filler

3DES(name+title) ECB, 15 GUIDs, seed 10

Metadata

Post ID: 1166iw
Title: 201210082126 → 2012-10-08 21:26 on A858's clock
Posted (UTC): 2012-10-09 01:26:39
Timezone: UTC−4 · title 21:26 against posted 01:26 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 976 hex characters · 488 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210082126) = 9363e4179b8429d80dbd575e29805e6e (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 15
Filler GUID seed: new Random(10).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 484 · predicted N = 15 ✓
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: 976 hex characters = 488 bytes = 61 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210082126 (name+title). Key = MD5(password) = 9363e4179b8429d80dbd575e29805e6e, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 15 GUIDs as hex (shown below).

Decrypted: GUID list

  1 bf443b0c-d538-8372-8908-e34850f8c0cf
  2 2a09861d-1c53-651b-9270-55a4741ef661
  3 63f21d47-47cc-6e24-8666-75f7c6e7dc59
  4 bf5c9ebc-ce07-6afe-8e1e-0760fad24009
  5 22bae2bb-2c2f-6dbe-b60e-0a3a3dde7e34
  6 425116e5-223a-2819-a4a9-4e75c5ce3566
  7 8d0f8f8e-5fa1-36ca-98f7-f8196af0c698
  8 41b7ed8e-9b6c-40e3-b7fe-452909d20567
  9 26b18dbe-606b-17a1-8cf2-de6b7584969f
 10 3d69ddbb-b685-8c81-801a-9d140f165773
 11 84f9b1b7-c356-594a-af36-0937dafb8bc5
 12 05cdf6a4-8343-26db-8d22-fb9ddf00af8d
 13 96e46f6d-d8e1-453a-8010-0479713e2c15
 14 8bae20ae-fc5e-6f24-9e63-770dc324142e
 15 99469f11-89a8-87e5-b102-2d0c9dfa54bb

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 866662341852468. Exactly this sequence comes out of new Random(10).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 484 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 15; the post has N = 15 ✓. 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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