201210090026 116i9f

explained decrypted filler

3DES(name+title) ECB, 20 GUIDs, seed 228

Metadata

Post ID: 116i9f
Title: 201210090026 → 2012-10-09 00:26 on A858's clock
Posted (UTC): 2012-10-09 04:26:47
Timezone: UTC−4 · title 00:26 against posted 04:26 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210090026) = 3ca30f2619400cc702ebf78ec7e08a94 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(228).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 493 · predicted N = 20 ✓
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: 0 · 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 = A858DE45F56D9BC9201210090026 (name+title). Key = MD5(password) = 3ca30f2619400cc702ebf78ec7e08a94, 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 a9704fd2-41b8-72fe-83ad-c4f677590ad2
  2 e533c838-62f7-60a9-a584-b820e05f9f34
  3 666786ec-86dc-1c84-b869-f21f981a26d1
  4 36ebb65b-1d4b-2e7d-93d2-e4fe0a4cf520
  5 c2025184-7d9b-1ec1-808f-476636ed7df6
  6 d50d4ed2-68b5-779a-afa9-6ef34437f0ed
  7 fe2095fa-1083-0c76-8566-c9c7804a0fba
  8 07ff34dc-95ff-7d9c-9be6-d0b7ac5d9304
  9 98c0c7b9-b743-1fb6-b904-8840c4dd8683
 10 41eedf1d-7878-3ce1-a926-ccbb1921a506
 11 a755d9dc-d8ab-2ec1-97eb-92d2425e43f8
 12 ae6b17ad-5492-4258-81fc-9f856ccdaf02
 13 b3615c7c-860f-3293-aebf-6fd8f8b8b56f
 14 90e3528f-f8ec-05a8-af5f-9cf119fc1178
 15 f38f548f-7baa-5df0-a63a-c7f602be13cc
 16 cf620e29-3542-365d-a977-3c33115dcd8f
 17 479ea661-ea39-6f6e-beea-8c2f5be6ed40
 18 79912e7f-9cd3-32bf-899e-e7b5ea1a7768
 19 f7ad9597-a802-7f2f-b466-5f09224995e0
 20 97aa4674-1379-5a0a-81e5-4f7112e004ee

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 76121707132430536375. Exactly this sequence comes out of new Random(228).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 493 of Run 35 (seed 854,622,578): new Random(854622578), 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 10:16–10:36).
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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