201211082245 12uw6b

explained decrypted filler

seed 409

Metadata

Post ID: 12uw6b
Title: 201211082245 → 2012-11-08 22:45 on A858's clock
Posted (UTC): 2012-11-08 14:45:40
Timezone: UTC+8 · title 22:45 against posted 14:45 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,424 hex characters · 712 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201211082245) = 97835ad9d8f14cf8654389962cc68d78 (name+title)
GUIDs: 22
Filler GUID seed: new Random(409).Next(9) ✓ verified
Run: Run 38 (seed 1,045,884,937) (seed)
Draw: 134 · predicted N = 22 ✓
Machine boot: 2012-10-11 03:41–03:51 (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: 1,424 hex characters = 712 bytes = 89 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201211082245 (name+title). Key = MD5(password) = 97835ad9d8f14cf8654389962cc68d78, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 22 GUIDs as hex (shown below).

Decrypted: GUID list

  1 e3295ea1-20f4-3e33-85a3-f6ed536c8d9a
  2 ecbbcca9-3bd6-728e-96bc-cf64229908ad
  3 7684d20e-e1a1-5ae0-9119-d1af750a863c
  4 028c57e5-921a-7fe5-aecd-b1a7fcfecc49
  5 a4c3309a-0ae6-7db5-b4a7-74d72bb0d558
  6 1d8c6411-4a23-88c2-a247-665b5bfb893e
  7 e91fa2ac-16ec-17ea-9c0c-0c5ff2360b88
  8 46836293-2424-580c-ae88-5d7456bd434d
  9 6b38aaca-ad8d-5ff5-9d63-d17cce35d424
 10 02bde78f-91c6-0770-8bba-bfa34780cc6d
 11 fe130dd6-84dd-5790-aefa-feb7362f620d
 12 eb0bdac5-2da1-7ebe-97c6-c8a9aff78e5c
 13 6043ccbe-56b4-7ff9-8cbb-48456b2e8b78
 14 c317f9b9-7566-2689-8c70-e9138b23199a
 15 8fa414c6-dd57-2b19-84ef-ab05e88fce4d
 16 47404286-1b5b-42d9-97cb-38fc81e7d4d7
 17 3b9ffbb1-13fd-7aaf-958a-d9c137c748cd
 18 193a7059-465d-55ec-bc0b-e815d6fbeef2
 19 03d4758d-2f73-6623-a7b6-867a22e51e19
 20 762fe063-c8e6-6e50-81c5-dcc55a7f196d
 21 7078d2d5-31ef-1a75-b738-70321fc29666
 22 61e46b40-a4d5-1a7c-82c3-cb1598602d63

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3757781550577224756611. Exactly this sequence comes out of new Random(409).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 134 of Run 38 (seed 1,045,884,937): new Random(1045884937), Next(8,64) per post. The RNG predicts N = 22; the post has N = 22 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-10-11 03:41–03:51).
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

Related