201209241214 10di73

explained decrypted filler

3DES(name+title) ECB, 20 GUIDs, seed 293

Metadata

Post ID: 10di73
Title: 201209241214 → 2012-09-24 12:14 on A858's clock
Posted (UTC): 2012-09-24 03:14:13
Timezone: UTC+9 · title 12:14 against posted 03:14 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209241214) = a18e9c7eea85f05661c64448b741d6ec (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(293).Next(9) ✓ verified
Run: Run 34 (seed 83,105,000) (seed)
Draw: 150 · predicted N = 20 ✓
Machine boot: 2012-09-22 10:23–10:24 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209241214 (name+title). Key = MD5(password) = a18e9c7eea85f05661c64448b741d6ec, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 94aad13e-8109-7cd1-980c-a3b72c2b8850
  2 7606d7fe-5ef6-7d04-b597-a5b42ac0ebd3
  3 e0ccc3c3-df45-5db4-bfd5-8bc31e21444d
  4 be6f84fd-69cb-0dcd-a502-1d42fa1aaf6d
  5 42711e2f-9b33-4785-b2ae-9315723bbb8d
  6 104c929f-38a5-5598-a50b-8fc2bf451e81
  7 2b0993a4-cf87-1afb-bc6c-27c0f47a4e92
  8 78271a19-6ee3-386c-8b12-2ee6d38ba8e7
  9 428b3d53-1785-271f-bae0-14878866dc4f
 10 fcf04fda-7f03-2041-9c65-6dee6fb05c99
 11 a59d2c96-a177-123f-8721-1bf289ea9e9c
 12 588d0c8c-db98-1aaa-b390-274d0a14e2e1
 13 3509c394-5777-0025-8609-c087003bebeb
 14 ca65f25e-1cd5-8211-a171-67f7b4b2cf88
 15 24e96f68-0178-0a79-a4ba-713d75e30d44
 16 b1f67036-d0bf-0930-87f2-3f10e370f3e1
 17 ec7f01aa-035f-0496-8844-7f24a225ee92
 18 407a87dc-1438-5d7d-bea7-134c376f3f10
 19 f6c3977a-54b8-5d4f-bc9c-cdd13d1f1d02
 20 aff3bdc7-ca73-62f1-a28c-aae9165af79c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 77504513221108000556. Exactly this sequence comes out of new Random(293).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 150 of Run 34 (seed 83,105,000): new Random(83105000), Next(8,64) per post. The RNG predicts N = 20; the post has N = 20 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:23–10:24).
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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