A858DE45F56D9BC9 archive

201212070000 14dz48

explained decrypted filler

seed 99

Metadata

Post ID
14dz48
Title
201212070000 → 2012-12-07 00:00 on A858's clock
Posted (UTC)
2012-12-06 16:00:18
Timezone
UTC+8 · title 00:00 against posted 16:00 UTC
Author
[deleted]
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
1,040 hex characters · 520 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9201212070000) = af0c7166192f4d60976f4f0e939ddfd2 (name+title)
GUIDs
16
Filler GUID seed
new Random(99).Next(9) ✓ verified
Run
Run 39 (seed 1,106,402,812) (seed)
Draw
70 · 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
0 · 0
Tags
automated (decryptable)2012Encrypted masked GUID listeditedkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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
Other archived version (the post was edited)
0
  • Read the ciphertext. Strip whitespace: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9201212070000 (name+title). Key = MD5(password) = af0c7166192f4d60976f4f0e939ddfd2, 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 8345d5c9-7bed-4c3b-88ee-5625da208395
  2 784bc696-6c47-787f-9c51-96d6d9b8c71c
  3 17998f4c-7680-8593-a116-6c6a9836f78b
  4 421285dc-9255-676d-83fa-58b6b9e915a1
  5 b429e22c-74f0-8411-acb6-40b9d40bbf70
  6 5c8a170e-b643-0f3a-8322-58468e215392
  7 57caca71-a5cf-2306-81c6-39754c4db9e9
  8 edce9280-6eac-0f55-9b55-6d97d0cce811
  9 613b59a4-dcb4-29ee-95ea-72c59c196099
 10 c2a7ad0d-443d-7f01-8508-fd1bb09988e3
 11 40aa4f8b-e514-2f64-9845-23d111fa03cd
 12 7d6675da-6e66-6193-98f5-8a3ba32adb6c
 13 0b1fff54-8138-6a1c-b359-b0e042c44bd7
 14 32011e03-090a-8556-b1ea-d158e0a0de9a
 15 7ad458e1-6890-281a-9448-fa01279f09a7
 16 c9eb6846-8c5e-7bdf-8a35-6efb864fcd9c

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 4786802027266827. Exactly this sequence comes out of new Random(99).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 70 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).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs