201210060223 11173h

explained decrypted filler

3DES(name+title) ECB, 8 GUIDs, seed 245

Metadata

Post ID: 11173h
Title: 201210060223 → 2012-10-06 02:23 on A858's clock
Posted (UTC): 2012-10-06 06:23:54
Timezone: UTC−4 · title 02:23 against posted 06:23 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 528 hex characters · 264 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210060223) = 7a9efd76300769a5d594e06bd84945c0 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 8
Filler GUID seed: new Random(245).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 283 · predicted N = 8 ✓
Machine boot: 2012-09-22 10:16–10:36 (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)

5217C37220722B5F 3E6583A9C5C04365 A6DB5D48B9391012 C8D53D8A7E2BC27F 3956AE2AB5419DD8 7B3AAC2452E260F3 3D2AAEC98721BC5C 0CF43234CB5745EA 0029744900530A4D F2275B0FDD343467 F0D70D4A25A8128E 53CEB5609C4EF35E EF0687797E80B796 DDAF3635A602999F 4095062B134B58F2 25675F4B26E61C7D 1BB2F17223B23461 389BA361702CABF5 FDD6715FA6F131AD 3D26A5BD9863B6E3 F05F0B848731C1BB CF84CC90F60353E3 CE07982AE93EF3B1 D4F0220936A97F13 278DE63CB4B0ABF3 46036CA222639CC8 F3555A419EEBBCC3 517F72257CBF64C6 9236A580E16F26C3 4775811F18D0C35A DCB48490D0F18A09 0771CE33896A0BC4 BD941A1ED7FEAC29

Read the ciphertext. Strip whitespace: 528 hex characters = 264 bytes = 33 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210060223 (name+title). Key = MD5(password) = 7a9efd76300769a5d594e06bd84945c0, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 8 GUIDs as hex (shown below).

Decrypted: GUID list

  1 315d33d8-8981-62e9-85cb-74ef209e2ec0
  2 2de2ae30-8939-6e02-af39-5d3c4434ff1a
  3 d60e3790-41ef-09c6-be1f-a440674c89df
  4 190502f2-fcec-7f7c-aace-7659e9a02ad7
  5 a3da060f-936a-7095-bcbe-1cdbfd675b0b
  6 e6be39b3-b241-5196-900c-bb1e4f9a2279
  7 5e580287-1df2-6942-9293-17c9213421da
  8 353731de-ea22-302b-8e49-5bfef0f5079b

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 66077563. Exactly this sequence comes out of new Random(245).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 283 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 8; the post has N = 8 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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