201206261055 vn1el

explained decrypted filler

seed 244

Metadata

Post ID: vn1el
Title: 201206261055 → 2012-06-26 10:55 on A858's clock
Posted (UTC): 2012-06-26 17:53:23
Timezone: UTC−7 · title 10:55 against posted 17:53 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(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
GUIDs: 14
Filler GUID seed: new Random(244).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 8 · predicted N = 14 ✓
Machine boot: 2012-06-14 10:25–10:26 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 10 · 1
Tags: automated (decryptable)2012Encrypted masked GUID listkey: namerun: 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 = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, 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 b5585e23-f0b1-1640-abd8-408806ddba8c
  2 609a2d7c-8b57-3ced-ad94-8165061257a6
  3 1944ab7c-2d98-2ef6-af0c-bb8d485a925e
  4 608c41b7-f488-50a8-be27-563f5ae153dc
  5 7eae3b3e-6c32-3bec-b72e-f398efe24b0c
  6 9f3b3892-d796-7d2b-b139-c3168045dd52
  7 7b9d2f09-2b8b-2cd5-b46a-3b548356a797
  8 e2c03b91-f8fb-7d1e-ab33-11f8d27f32c5
  9 5750150a-42b8-11d9-9c17-8160623c7e36
 10 d767d633-3029-243c-88fa-e52e85b0cdbf
 11 15f9245c-a31b-0835-b984-ba5e1f0e4607
 12 3c94cee3-5693-867c-975d-a70bce83b19f
 13 40b012a4-2147-3a5e-97b3-e2d881d2807f
 14 739b8b48-50a6-3ec2-a8ad-3debecce0ae0

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 13253727120833. Exactly this sequence comes out of new Random(244).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 8 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) 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 2012-06-14 10:25–10:26).
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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