201309100059 1m24a4

explained decrypted filler

seed 375

Metadata

Post ID: 1m24a4
Title: 201309100059 → 2013-09-10 00:59 on A858's clock
Posted (UTC): 2013-09-09 20:59:48
Timezone: UTC+4 · title 00:59 against posted 20:59 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(A858DE45F56D9BC9201309100059) = dfc1bfe88d90489d46930431830f9103 (name+title)
GUIDs: 16
Filler GUID seed: new Random(375).Next(9) ✓ verified
Run: Run 52 (seed 1,430,705,843) (seed)
Draw: 80 · predicted N = 16 ✓
Machine boot: 2013-08-14 07:34–10:34 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 5 · 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 = A858DE45F56D9BC9201309100059 (name+title). Key = MD5(password) = dfc1bfe88d90489d46930431830f9103, 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 23f36f4d-1044-5385-9878-c5bbe91ce7c2
  2 bc0be2c7-25ad-7454-bb5a-6dc30c1af3a3
  3 45e46589-51d7-70de-a91b-cc53d1ff0c1d
  4 f47b2a04-6487-5dbb-ad4e-f592a32a471d
  5 330e57dc-3bfb-4fce-a4e5-7762015fb24e
  6 186c3f22-6af9-22d5-9d5c-ab0fd5af8781
  7 6de37669-dd42-84df-b1af-3f754d43dfbe
  8 c34baf55-c99f-5cc1-9a50-257eeb2d6fcb
  9 babdf385-901e-372d-a4a1-d8841504132e
 10 b421cf5a-065e-41b9-b88f-46b52370a237
 11 4262b3e2-eec8-57ad-992c-22c5f496b689
 12 378bb836-9e77-2ae7-be78-74e335ad3973
 13 c23e35aa-6e21-3f69-9e57-8a8b81cdf5c4
 14 f917db34-c798-5dc1-83ec-8cb70847d801
 15 3e224d54-fcdd-4c85-b995-b34b1b00f40c
 16 422881b3-7999-2a17-913e-aef2ab885c67

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 5775428534523542. Exactly this sequence comes out of new Random(375).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 80 of Run 52 (seed 1,430,705,843): new Random(1430705843), 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 2013-08-14 07:34–10:34).
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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