201210240222 11zt1p

explained decrypted filler

3DES(name+title) ECB, 16 GUIDs, seed 852

Metadata

Post ID: 11zt1p
Title: 201210240222 → 2012-10-24 02:22 on A858's clock
Posted (UTC): 2012-10-24 06:23:00
Timezone: UTC−4 · title 02:22 against posted 06:23 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(A858DE45F56D9BC9201210240222) = b190074c25043d591b43687a721aab34 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(852).Next(9) ✓ verified
Run: Run 38 (seed 1,045,884,937) (seed)
Draw: 2 · predicted N = 16 ✓
Machine boot: 2012-10-11 03:41–03:51 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 0 · 1
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: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210240222 (name+title). Key = MD5(password) = b190074c25043d591b43687a721aab34, 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 34bd302a-7645-7242-9745-2094822dcba1
  2 62b935f5-71ff-707c-9f7e-d516612abe4b
  3 f06a7d37-3df8-2f1d-aa3d-1a2caad48c1d
  4 3138c0dc-ca95-35ce-88e0-f06b838a085c
  5 93960c5b-249f-7899-8e0c-5295bffbed97
  6 88c1ac98-0105-1d2a-8490-693574683272
  7 e86ceec1-6568-5c4f-b139-f3dc2eb09c7d
  8 950d5b1b-9c67-7653-b4c5-21960b19dfd9
  9 e528484f-6829-3da7-a595-70f28ca9bb23
 10 1c7b51c3-4e73-40dd-886a-7a6f9899b4ce
 11 53a44e49-2d5a-8703-b02c-6d8f5c15f5b9
 12 72037fa8-d352-5c14-8371-3f490fc3e26b
 13 ddd757a8-85e2-3bb5-ad82-4805c090bbf1
 14 abb0994f-073f-6615-be89-3798e0ec474b
 15 5936c50b-d590-300b-851f-71c1ee6c818e
 16 ce3dc7e2-86ce-170b-badb-e005940768a6

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 7723715734853631. Exactly this sequence comes out of new Random(852).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 2 of Run 38 (seed 1,045,884,937): new Random(1045884937), 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 2012-10-11 03:41–03:51).
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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