201309140359 1md85x

explained decrypted filler

seed 27

Metadata

Post ID: 1md85x
Title: 201309140359 → 2013-09-14 03:59 on A858's clock
Posted (UTC): 2013-09-14 07:59:58
Timezone: UTC−4 · title 03:59 against posted 07:59 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201309140359) = d1b36b1e1d105c5392c1fef8fab8eaec (name+title)
GUIDs: 20
Filler GUID seed: new Random(27).Next(9) ✓ verified
Run: Run 53 (seed 26,950,390) (seed)
Draw: 39 · predicted N = 20 ✓
Machine boot: 2013-09-12 09:30–10:30 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 6 · 0
Tags: automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201309140359 (name+title). Key = MD5(password) = d1b36b1e1d105c5392c1fef8fab8eaec, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 8be2a4ce-90a0-7f35-979c-b9a7fd03dab4
  2 4dcc2027-ace1-6463-8fb7-9de51bd60a06
  3 0013b62b-c962-5614-ab54-152cfa4ff033
  4 2809a887-0976-2378-b5d7-52d0bed70e1f
  5 f7df2563-25d5-3e50-a1d5-07083a88797d
  6 26554431-1246-1f37-b4a4-bee3db04cc01
  7 adaed554-b38f-0571-b2a3-fa35b0946fee
  8 581f5565-7718-89a6-89ba-eb3c1134a0ae
  9 459f921d-083c-26f6-9874-42ed64476c18
 10 18e9444e-6180-207f-af95-a2d83ba85dff
 11 f0de879d-3967-1508-9995-d6b52698ed89
 12 bb518fb6-85cb-494a-9396-a17214b63209
 13 7a78afac-29b5-1eb5-b9c0-9e89fad1f702
 14 9540f718-122b-4b1a-a41b-f98878e36875
 15 b7778d5f-b341-79b0-8634-29f48b6bba5c
 16 31c0471e-1cef-841c-8650-a7cdc3583f8b
 17 2ca7d424-1d13-1e61-986f-ba5ddc58047d
 18 c4bffe75-0cca-65f3-bcb5-2ef449d13f14
 19 bdbfbaff-e2db-3149-8351-7fbb43bbf337
 20 7d064049-bcd1-627d-8dfc-0aa37e74660e

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 76523108221414781636. Exactly this sequence comes out of new Random(27).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 39 of Run 53 (seed 26,950,390): new Random(26950390), 4·Next(1,12) per post. The RNG predicts N = 20; the post has N = 20 ✓. The seed is the machine's uptime in ms when the app started (boot 2013-09-12 09:30–10:30).
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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