201309031559 1lmzmv

explained decrypted filler

seed 794

Metadata

Post ID: 1lmzmv
Title: 201309031559 → 2013-09-03 15:59 on A858's clock
Posted (UTC): 2013-09-03 11:59:56
Timezone: UTC+4 · title 15:59 against posted 11:59 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 784 hex characters · 392 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201309031559) = d99a6e090505f8b57adc5850c258b459 (name+title)
GUIDs: 12
Filler GUID seed: new Random(794).Next(9) ✓ verified
Run: Run 52 (seed 1,430,705,843) (seed)
Draw: 29 · predicted N = 12 ✓
Machine boot: 2013-08-14 07:34–10:34 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 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: 784 hex characters = 392 bytes = 49 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201309031559 (name+title). Key = MD5(password) = d99a6e090505f8b57adc5850c258b459, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 12 GUIDs as hex (shown below).

Decrypted: GUID list

  1 c32fba12-aacc-4f37-8e3c-71a4f0c9b73c
  2 929a429b-0f7e-7cb3-ba37-887dc21ac165
  3 7c15aa69-78a1-6069-be88-89c2fc677954
  4 be8025c4-0f24-0e01-9a16-f433dfcc228c
  5 dd0e2599-b11e-623f-9172-a62ced59479f
  6 d44e0551-8370-3060-80f0-49245f7059ee
  7 8f290cce-dacc-5e68-ab28-35733261c984
  8 fcb0b1f2-9919-7a1f-a9ed-0f0ff76977d7
  9 32e8adde-de05-12f6-8d41-7b2cab9b17b3
 10 1d1bf7c3-729c-09d3-a083-1a0e6007a83a
 11 24561b38-bb8b-21c5-8221-8d92dd8f3478
 12 293467e2-0c9f-3023-b294-f261822f8328

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 476063571023. Exactly this sequence comes out of new Random(794).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 29 of Run 52 (seed 1,430,705,843): new Random(1430705843), 4·Next(1,12) per post. The RNG predicts N = 12; the post has N = 12 ✓. The seed is the machine's uptime in ms when the app started (boot 2013-08-14 07:34–10:34).
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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