201206261625 vnmrv

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 186

Metadata

Post ID: vnmrv
Title: 201206261625 → 2012-06-26 16:25 on A858's clock
Posted (UTC): 2012-06-26 23:23:21
Timezone: UTC−7 · title 16:25 against posted 23:23 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(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(186).Next(9) ✓ verified
Run: Run 6 (seed 652,173,660) (seed)
Draw: 4 · predicted N = 16 ✓
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: 1,040 hex characters = 520 bytes = 65 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 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 2ca5e938-0b95-876f-8bac-d1709328d075
  2 9fcf16f0-c412-39ea-96d3-e75b59b3a293
  3 9ef5696b-c3de-7299-891b-59390ff20726
  4 a8f81f65-9fb6-277d-a394-1b288046196b
  5 2e898af4-dd9e-1820-9d22-9e320588414e
  6 d6857128-01f5-04eb-afdb-3562344adecc
  7 b77dd873-b9cf-2d1c-adfd-586e66afbf77
  8 d0f52f99-7156-6902-afe3-541c4c5ba02f
  9 e26d455d-ce4f-8e10-9c12-fb880989907a
 10 d6a27d68-76e6-7669-98dd-356df127a3b9
 11 1f9258e2-7524-2aa3-8444-d62013660609
 12 f779e5ca-a429-6390-8d16-a1becbad745a
 13 3e78c723-4945-40f1-996f-5f5682b895fe
 14 68ef3de4-afb2-2221-ae8b-77675c00cded
 15 d44d92f6-6ba6-1e13-bf5e-bdfa21c30a87
 16 0c0c74a1-f717-1aee-81d2-8044d29d437c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 8372102687264211. Exactly this sequence comes out of new Random(186).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 4 of Run 6 (seed 652,173,660): new Random(652173660), Next(8,24) 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 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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