201309190632 1mpb57

explained decrypted filler

seed 935

Metadata

Post ID: 1mpb57
Title: 201309190632 → 2013-09-19 06:32 on A858's clock
Posted (UTC): 2013-09-19 10:32:58
Timezone: UTC−4 · title 06:32 against posted 10:32 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(A858DE45F56D9BC9201309190632) = 453b814f0f4a58296a9d9d46b99885f3 (name+title)
GUIDs: 20
Filler GUID seed: new Random(935).Next(9) ✓ verified
Run: Run 53 (seed 26,950,390) (seed)
Draw: 112 · predicted N = 20 ✓
Machine boot: 2013-09-12 09:30–10:30 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201309190632 (name+title). Key = MD5(password) = 453b814f0f4a58296a9d9d46b99885f3, 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 c4a013f6-8474-1065-ab43-461b7a5e355a
  2 da35dbed-14b4-1da5-ac82-54c06eeb786b
  3 97dcdc63-6b11-2743-9c6d-9c980fba0d8c
  4 ce6dcab0-cf3b-1435-a515-d5f1258bf868
  5 471c8ee3-75a9-3d2b-9efe-516de3a843ab
  6 29f0f2bc-40d4-5b9e-95a4-f6223d599018
  7 018c3ef4-6513-741b-92a0-0b5ae4346695
  8 2834d51b-0cd8-4471-a826-1cc91e6f5088
  9 6fe94641-2342-5167-8341-0b862ec873f4
 10 99e281e8-7a0a-061b-a42f-d8894e0a5034
 11 74b01b9a-fdd0-1d21-b96e-902ab770319b
 12 6e1a5a54-de53-3208-80b2-4758fe7020a8
 13 cae7aa43-7244-3dc7-8b81-31ee084a10d3
 14 e5896e1e-6098-883d-a624-fe2b08d6c5e6
 15 fd64dbf8-be66-4577-b8c4-9e412aab6f8b
 16 3975db4b-e947-8bd1-be0e-0e2905a744ad
 17 06dd0dc3-22da-8e6e-b532-04a4207bfb0a
 18 487dbd90-f2c2-6190-8a0f-6aaa0ef41696
 19 af2ed6e3-e9da-80cd-a31d-a6af73a5a34a
 20 8e1d45cf-c19b-3fdf-9c5a-3e7ab9072480

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 11213574501338488683. Exactly this sequence comes out of new Random(935).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 112 of Run 53 (seed 26,950,390): new Random(26950390), 4·Next(1,12) 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 2013-09-12 09:30–10:30).
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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