201210081526 115ht1

explained decrypted filler

seed 133

Metadata

Post ID: 115ht1
Title: 201210081526 → 2012-10-08 15:26 on A858's clock
Posted (UTC): 2012-10-08 19:26:17
Timezone: UTC−4 · title 15:26 against posted 19:26 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(A858DE45F56D9BC9201210081526) = b2659c599214f05980deae94b022a6cf (name+title)
GUIDs: 14
Filler GUID seed: new Random(133).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 466 · predicted N = 14 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 12 · 1
Tags: automated (decryptable)2012Encrypted masked GUID listkey: 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 = A858DE45F56D9BC9201210081526 (name+title). Key = MD5(password) = b2659c599214f05980deae94b022a6cf, 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 a43ce20e-a190-1bfd-92fe-2bfa75793593
  2 c6d682e7-da96-72cb-b1b1-d1560b83c9f3
  3 a6c11786-0f9c-60f7-bd51-0709d868a8dd
  4 653abee7-de19-8d47-8148-9c9743000c32
  5 8e70d556-5d93-2fce-a5a8-db62042d5057
  6 9e4b606d-ad3d-780d-ac29-9173008f9aa6
  7 e046b147-bf20-48cd-8d75-c0917c974cc1
  8 8f83bc11-d6ac-1b6a-8fbc-abc141b4f5a4
  9 b9449c7a-f604-3b5c-99b2-23a7547bbb84
 10 24e24c58-6518-27c9-8771-5519746ff298
 11 ac62954c-bca9-25f9-a22f-d70fd08dbb34
 12 31eecc81-b0fc-28c8-84a9-ac548177a474
 13 e1053297-775d-00bc-a744-cb0f83800a80
 14 24f1aa12-dc62-5626-b1b9-43acf0bd9547

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 17682741322205. Exactly this sequence comes out of new Random(133).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 466 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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