201210081646 115n80

explained decrypted filler

3DES(name+title) ECB, 14 GUIDs, seed 401

Metadata

Post ID: 115n80
Title: 201210081646 → 2012-10-08 16:46 on A858's clock
Posted (UTC): 2012-10-08 20:46:27
Timezone: UTC−4 · title 16:46 against posted 20:46 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(A858DE45F56D9BC9201210081646) = 9215a48c2c95a4800366ef3701d30b3a (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 14
Filler GUID seed: new Random(401).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 470 · predicted N = 14 ✓
Machine boot: 2012-09-22 10:16–10:36 (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: name+titlerun: 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 = A858DE45F56D9BC9201210081646 (name+title). Key = MD5(password) = 9215a48c2c95a4800366ef3701d30b3a, 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 b5eba814-52d3-116a-bcf4-254645d10d19
  2 13223834-1240-4c07-af21-50a3fbe237c7
  3 3dbe2593-6d7d-0f90-a40c-1724bd34632f
  4 e1161b4b-5245-1890-860e-9600a1a35e56
  5 1841bd9b-8022-270b-b841-66b51c1385b0
  6 48b29dae-371d-80b9-b743-9fc6c916b7f5
  7 46544108-9c71-590d-9ebd-e7b165a7cfc6
  8 78eb93a6-d897-59f3-ae9b-5abf8807cdea
  9 104ea45e-1ef5-5b5b-89a7-684e4d60c620
 10 0dbcd4f5-e09d-16bc-a2e3-2833008e2b76
 11 8fafa72d-f308-61dd-b7da-79727ab51413
 12 bc6827e4-e336-4423-9d66-5064573e3d59
 13 563220f4-e961-263e-a1ee-d3130f21c278
 14 301468e1-7344-0bc3-825d-647fc6390869

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 14012855516420. Exactly this sequence comes out of new Random(401).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 470 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) 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 2012-09-22 10:16–10:36).
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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