201309141359 1mdxrh

explained decrypted filler

seed 532

Metadata

Post ID: 1mdxrh
Title: 201309141359 → 2013-09-14 13:59 on A858's clock
Posted (UTC): 2013-09-14 17:59:58
Timezone: UTC−4 · title 13:59 against posted 17:59 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(A858DE45F56D9BC9201309141359) = 65e4389588d8e3282400e67a2fb34e98 (name+title)
GUIDs: 16
Filler GUID seed: new Random(532).Next(9) ✓ verified
Run: Run 53 (seed 26,950,390) (seed)
Draw: 49 · predicted N = 16 ✓
Machine boot: 2013-09-12 09:30–10:30 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 0
Tags: automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: 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 = A858DE45F56D9BC9201309141359 (name+title). Key = MD5(password) = 65e4389588d8e3282400e67a2fb34e98, 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 b0be79aa-7a13-5672-a84c-8d8fdf89d12a
  2 5763e7f2-829e-8c67-81e2-849050e4ec6a
  3 5ab753f4-ed6f-51d6-92be-e58041885268
  4 1537a2bc-8491-0789-a39b-570e622bb3d3
  5 243dd549-89be-33d7-89d1-358ca4a27535
  6 3fe1c4dd-4395-4975-9b02-f0fd5d6afffb
  7 b1c68893-b36c-2f5b-8f48-d5cf0fb6ff86
  8 25896548-09f6-3f9a-8f4c-1d4890f930f2
  9 739b34f5-7a49-7877-b1b4-ccd2ec01c426
 10 971ca5ef-8860-493c-a6d1-03db12ce51a4
 11 42df1240-a6e9-22c1-9d0d-1725aeb80615
 12 ce6c107c-a354-75bc-9575-8cd84c0ce161
 13 fd01b43c-8f7e-3277-b13d-348fa0d3e2dd
 14 f8e18e7a-7573-29e2-838e-418e847efb52
 15 eb737d75-119d-3506-94fd-c870c8518956
 16 cbf34776-f360-2dc7-a8e8-3a8f95db8644

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 5850342374273232. Exactly this sequence comes out of new Random(532).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 49 of Run 53 (seed 26,950,390): new Random(26950390), 4·Next(1,12) 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 2013-09-12 09:30–10:30).
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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