201206270815 vnpkh

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 574

Metadata

Post ID: vnpkh
Title: 201206270815 → 2012-06-27 08:15 on A858's clock
Posted (UTC): 2012-06-27 00:13:45
Timezone: UTC+8 · title 08:15 against posted 00:13 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,104 hex characters · 552 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 17
Filler GUID seed: new Random(574).Next(9) ✓ verified
Run: Run 6 (seed 652,173,660) (seed)
Draw: 11 · predicted N = 17 ✓
Machine boot: F 2012-05-15 19:06–19:16 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: namerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,104 hex characters = 552 bytes = 69 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 17 GUIDs as hex (shown below).

Decrypted: GUID list

  1 d6063bf0-2209-5c66-9e37-9886959b40d1
  2 762e61fa-e11a-2010-830b-1960b18a5337
  3 2126e813-7bb5-83df-b237-14d7df462f40
  4 c9f8a05d-362c-007c-af03-50669c1d61d9
  5 dd4021ac-d762-3753-91c0-15e35e1711e8
  6 6dfbc08c-2722-151a-9cdf-570a605a074c
  7 3e4a42f0-aa0d-0578-ad8b-ae51a93559b0
  8 5ea54026-2a6d-383b-8c5b-11612b161544
  9 f8158da0-8bfa-8882-91d1-d8cbbd894635
 10 b7ae16cf-c1ac-8213-bcc6-ad322600ff71
 11 ebd96d60-59db-1b83-a18d-e0f920b87d5f
 12 7f20411c-41a3-5c98-852c-6792c23af63d
 13 48610433-c4c7-2a87-9522-4b4891ecdc63
 14 3f07ad8f-1a3a-0e42-93a9-61c2c4c803cc
 15 b1a239af-87a5-6888-84ae-d4307df456c8
 16 ef88f3ad-8781-42d8-9cdf-7bb40aa35c44
 17 d5a3ceef-2a82-10db-970e-de639342953b

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 52803103881520641. Exactly this sequence comes out of new Random(574).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 11 of Run 6 (seed 652,173,660): new Random(652173660), Next(8,24) per post. The RNG predicts N = 17; the post has N = 17 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 19:06–19:16).
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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