A858DE45F56D9BC9 archive

201210101500 118nc8

explained decrypted filler

seed 935

Metadata

Post ID
118nc8
Title
201210101500 → 2012-10-10 15:00 on A858's clock
Posted (UTC)
2012-10-10 06:00:24
Timezone
UTC+9 · title 15:00 against posted 06:00 UTC
Author
[deleted]
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
1,936 hex characters · 968 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9201210101500) = 4a8ae5d35a5a68b4af5526a47f334243 (name+title)
GUIDs
30
Filler GUID seed
new Random(935).Next(9) ✓ verified
Run
Run 35 (seed 854,622,578) (seed)
Draw
520 · predicted N = 30 ✓
Machine boot
2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources
community-archive, arctic-shift · body from community-archive
Links
Reddit · Arctic Shift · JSON
Score · comments
0 · 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: 1,936 hex characters = 968 bytes = 121 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9201210101500 (name+title). Key = MD5(password) = 4a8ae5d35a5a68b4af5526a47f334243, used as a two-key 3DES key.
  • Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 30 GUIDs as hex (shown below).

Decrypted: GUID list

  1 de7e0122-ab6c-1511-92bf-4b9ca1abc0b9
  2 f93c6d4e-d920-1a4e-81e1-cf9ca090ed54
  3 28a7f0bb-d59c-263a-a568-cc2edac6f30c
  4 8af2e0e3-3fa0-1ee9-b47e-cd9def4a4824
  5 97c18339-3583-3675-b99e-688896e86a40
  6 1cb4eae4-23ae-566a-8a7d-2d916288f0e6
  7 c71359fd-fa9d-7ca0-943f-139e0bed501b
  8 8684bf27-efd9-4565-88d0-37e88334ae75
  9 acef7ca9-cedd-56b1-bd29-079b5617ae1a
 10 278e20d6-dd74-0aa1-a98c-c8a9f21d26c9
 11 4d4043b9-a2f9-1261-b8a8-f4116da342ec
 12 9b983682-9b28-3c51-8b7d-7b226875c8c5
 13 72ca0cef-c79f-3c53-8fe3-6f83037f280d
 14 26d410e8-63d3-8826-b91a-d94a1bc25a1e
 15 9a8183c2-2ed7-43c0-ae65-5f81d0086e15
 16 0a79fbb4-55c3-8e56-937a-d33d4d0a05d4
 17 0ed3b30a-b758-8cca-9c28-0236beb25c6f
 18 645b66ae-58d2-6709-9820-8584fdcc4fc2
 19 67dcdf65-31dd-8709-a071-69fb1921d41b
 20 b79d852e-92f7-3d25-b293-78883df9110f
 21 8e7cdbb0-344e-030d-8490-d4df0cc1501d
 22 f2c5168e-f35b-21be-9f43-972e6f70949b
 23 bf478738-0b36-00ed-9227-b56a823605e5
 24 bf6a2477-f8f7-64ca-a3de-4b93c9913ad2
 25 e5d5767b-1e14-3859-8778-7cefddf2c458
 26 cc968d26-94a8-83c3-919a-7c2d6375b16d
 27 9bfaeb09-474f-7dc4-a47d-57306ef2e9d6
 28 2e9f85c2-e124-09ed-bbd1-7c813b874d1b
 29 a702af88-27a1-7dfd-83fa-4b6ff01048cb
 30 ac5731d3-c3f5-0305-be90-379e04284b41

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 112135745013384886830206387070. 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.
  2. Explain the count. This post is draw 520 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 30; the post has N = 30 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs