A858DE45F56D9BC9 archive

201206261125 vn3jh

explained decrypted filler

seed 35

Metadata

Post ID
vn3jh
Title
201206261125 → 2012-06-26 11:25 on A858's clock
Posted (UTC)
2012-06-26 18:23:48
Timezone
UTC−7 · title 11:25 against posted 18:23 UTC
Author
[deleted]
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
1,168 hex characters · 584 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
GUIDs
18
Filler GUID seed
new Random(35).Next(9) ✓ verified
Run
Run 3 (seed 1,063,142,882) (seed)
Draw
27 · predicted N = 18 ✓
Machine boot
2012-06-14 10:25–10:26 (seed = uptime at app start)
Sources
community-archive, arctic-shift · body from community-archive
Links
Reddit · Arctic Shift · JSON
Score · comments
9 · 0
Tags
automated (decryptable)2012Encrypted masked GUID listkey: namerun: seed

From the post to its content

As posted (encrypted)

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
  • Read the ciphertext. Strip whitespace: 1,168 hex characters = 584 bytes = 73 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, used as a two-key 3DES key.
  • Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 18 GUIDs as hex (shown below).

Decrypted: GUID list

  1 8353148e-f223-0b39-9173-3ff036fecc41
  2 96d50c32-8a99-0a9f-8420-5b7a22501cfa
  3 2cf3a29e-539b-2b1d-a201-c7bf36537c51
  4 979831ab-ae0d-08f8-8dfd-6ef75ad79ebb
  5 0cce31e3-2a31-0502-bd15-c3fefba38644
  6 b78d75fb-0eda-12ef-bc70-8d37dbbca1fe
  7 62438151-8c32-59a0-86d7-49ef521e2d1f
  8 394245b9-04a4-01c2-87e9-e815d852b6e1
  9 2c0a30a4-b0a6-2f25-b265-29b163bfd6dd
 10 6d738521-85dc-1215-81f7-181ac6edc9ae
 11 52637f45-b221-04e3-8085-6b139d8ef03c
 12 27f90edf-4867-78fe-9b83-72e533e1b634
 13 f1900f41-3902-61fc-bd5d-8a1eabf3d6ea
 14 59c2473c-e799-6186-8dcc-1710a5d81482
 15 04e4cee9-c4e2-4f82-940e-af5c8618f50a
 16 c60de0f4-1e16-7e89-9b99-1bb52f77210c
 17 2c1771d4-cbd3-5dcb-a596-d0fca23bae22
 18 be124dfa-3a24-6cc5-92dd-7f58e21b5fd7

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 002001502107664756. Exactly this sequence comes out of new Random(35).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 27 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) per post. The RNG predicts N = 18; the post has N = 18 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-06-14 10:25–10:26).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs