201209241215 10di9f

explained decrypted filler

3DES(name+title) ECB, 19 GUIDs, seed 776

Metadata

Post ID: 10di9f
Title: 201209241215 → 2012-09-24 12:15 on A858's clock
Posted (UTC): 2012-09-24 03:15:14
Timezone: UTC+9 · title 12:15 against posted 03:15 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,232 hex characters · 616 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209241215) = 7f7f965f5785e4069b0106faa3b69f85 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 19
Filler GUID seed: new Random(776).Next(9) ✓ verified
Run: Run 34 (seed 83,105,000) (seed)
Draw: 151 · predicted N = 19 ✓
Machine boot: 2012-09-22 10:23–10:24 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,232 hex characters = 616 bytes = 77 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209241215 (name+title). Key = MD5(password) = 7f7f965f5785e4069b0106faa3b69f85, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 19 GUIDs as hex (shown below).

Decrypted: GUID list

  1 31ad4c14-53f1-10d4-85eb-4d8851b3b6ba
  2 62dd7e4b-470c-407e-939f-c73a2da7a78d
  3 28618c97-5409-13ad-8375-c079d2c1b09e
  4 58d2df7e-2b26-1dc3-be0e-b867d38b3277
  5 c372c3f2-0c95-5dd0-8c74-b16cbd27cec8
  6 28c1e8b2-f9b9-642c-8560-edc5545f8cf4
  7 11ce4079-29b9-5597-86bd-10db0f88881f
  8 30d95a61-53c8-66a5-a221-b8336e2d3cb9
  9 e0a86565-a494-81a3-adf8-cc91f38e655b
 10 934d9c7d-c334-37f0-8b22-ecbfb35378d3
 11 2fa0bafd-e0cb-8fbb-b644-615c45c13365
 12 51425b26-2f85-2e23-a0b3-039e314b615f
 13 9218636d-8c0f-0af4-a256-5414c58a8164
 14 f1b1454e-0793-17f3-aa78-8f1fe0ed3757
 15 59a37aaa-2c8a-112b-8516-680edd1a8771
 16 5bbf4f97-6ef4-5017-84b0-9e30a087d3c2
 17 00fbd26e-30cb-01a3-b746-bf39e41faf91
 18 31edffd4-be44-15e6-8abd-cfef0dc70477
 19 9e0da842-fdc8-6b06-b3c0-5b45e3cd4e42

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 1411565683820115016. Exactly this sequence comes out of new Random(776).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 151 of Run 34 (seed 83,105,000): new Random(83105000), Next(8,64) per post. The RNG predicts N = 19; the post has N = 19 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:23–10:24).
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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