201212031602 147xnw

explained decrypted filler

seed 763

Metadata

Post ID: 147xnw
Title: 201212031602 → 2012-12-03 16:02 on A858's clock
Posted (UTC): 2012-12-03 21:02:02
Timezone: UTC−5 · title 16:02 against posted 21:02 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(A858DE45F56D9BC9201212031602) = ae7abea3de560f7961c8a1129c31db0c (name+title)
GUIDs: 16
Filler GUID seed: new Random(763).Next(9) ✓ verified
Run: Run 39 (seed 1,106,402,812) (seed)
Draw: 3 · predicted N = 16 ✓
Machine boot: 2012-11-20 22:02–00:02 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 8 · 0
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: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201212031602 (name+title). Key = MD5(password) = ae7abea3de560f7961c8a1129c31db0c, 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 95cd59a8-d21c-32ee-9178-9a1144749ab5
  2 1fa5f1e1-df5d-6659-8327-ae56bf255c2b
  3 1f3a025c-633d-0e3f-b54e-068ef85901c3
  4 047edd13-7ccb-3500-bfa1-49c60af7ce2b
  5 61b7c6d2-4b11-6638-ac22-f4c53cc13bfb
  6 e7a48835-ec7a-3c56-8da5-3b82f0ff6e36
  7 d05bb91d-8ffe-6f62-9dca-3d60b15dee0e
  8 728e1312-7fc3-2c68-b7ed-b3e82eb436ac
  9 66e04f57-4a5d-3fff-8658-e504deb950ab
 10 eb9e6b12-c988-5226-803b-31d434ff61f5
 11 e56a8cc1-cd9e-3160-974a-a9bfc4700e03
 12 8ea03878-6bae-151a-bc1e-e0901c3f35f6
 13 22f465a6-259d-1419-ab62-a3a9c6fb485b
 14 0d4c7bba-59d2-33cd-9044-5c9b909f7727
 15 42b5f361-033b-0dd5-ba92-4fd494988115
 16 b5f531c0-4da3-4d26-8fd9-a782c7aca44a

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3603636235311304. Exactly this sequence comes out of new Random(763).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 3 of Run 39 (seed 1,106,402,812): new Random(1106402812), Next(8,64) 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 2012-11-20 22:02–00:02).
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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