201208011843 xjfng

explained decrypted filler

seed 179

Metadata

Post ID: xjfng
Title: 201208011843 → 2012-08-01 18:43 on A858's clock
Posted (UTC): 2012-08-02 01:40:37
Timezone: UTC−7 · title 18:43 against posted 01:40 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,360 hex characters · 680 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9A858DE45F56D9BC9) = 0dcc4bd9e114ebc42078977dc9125404 (name+name)
GUIDs: 21
Filler GUID seed: new Random(179).Next(9) ✓ verified
Run: Run 21 (seed 452,527,359) (seed)
Draw: 3 · predicted N = 21 ✓
Machine boot: 2012-07-27 18:58–19:13 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 4 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+namerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,360 hex characters = 680 bytes = 85 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9A858DE45F56D9BC9 (name+name). Key = MD5(password) = 0dcc4bd9e114ebc42078977dc9125404, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 21 GUIDs as hex (shown below).

Decrypted: GUID list

  1 cb4c7ee7-5848-21df-9154-88bcc1c17ccf
  2 808ecd88-7d19-3e5f-9819-920ec561e6ac
  3 72197ff7-6150-76d4-9bde-65975cf74642
  4 ccc22613-9fcd-60d6-9ab9-ee4f30ecdc70
  5 e039f1d1-f1b7-097a-a649-60f438c376ff
  6 0929c209-cf07-8e48-a917-f3c8179763d6
  7 7c90a8b8-544f-0dc6-b6e8-21efb2b6261a
  8 e363b2e8-3820-2ac6-ae81-e87cef1e610b
  9 216c2bb9-907a-1b14-8933-855670d494d1
 10 855f4106-d91c-26de-af47-d1cf74bdbf15
 11 5eb046a4-e7e8-1a1a-8121-8db2268c289d
 12 8f6c4810-817a-1d11-8a70-8c35098b7149
 13 799522ce-144c-6321-a4bb-0f2ce4d501e7
 14 a53fc70f-c615-5559-a33c-a2f09b4444ef
 15 15093874-2036-2271-a9d8-1452ff122e13
 16 d67b497b-edd0-77e9-a84f-487d8d71d06d
 17 0b5ee7a1-52fa-07ff-8b75-0bff9ee40534
 18 30cb12a6-c1ac-8e8c-94a2-dc9aa2b37345
 19 abc69429-0f88-4775-8eb2-7fbe588e7d57
 20 37bef2f1-bf9e-501f-bf06-d79d9df21422
 21 ff943166-ff48-5f79-9340-178fc0ebac5f

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 237608021211652708455. Exactly this sequence comes out of new Random(179).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 3 of Run 21 (seed 452,527,359): new Random(452527359), Next(8,64) per post. The RNG predicts N = 21; the post has N = 21 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-07-27 18:58–19:13).
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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