201209231457 10cosq

explained decrypted filler

3DES(name+title) ECB, 9 GUIDs, seed 802

Metadata

Post ID: 10cosq
Title: 201209231457 → 2012-09-23 14:57 on A858's clock
Posted (UTC): 2012-09-23 18:57:26
Timezone: UTC−4 · title 14:57 against posted 18:57 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 592 hex characters · 296 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209231457) = 99e95572c0c6f50187603f08031db5fc (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 9
Filler GUID seed: new Random(802).Next(9) ✓ verified
Run: Run 34 (seed 83,105,000) (seed)
Draw: 134 · predicted N = 9 ✓
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)

2A7AB68FC454577E C3FCA4A8EE682DA5 5DA9377DB7E20CAD 22F031712C1C3063 EC3031FE65EEFE6D 855083941851E3CE 8B395E3C6857BD23 20E430B03CB8FF9F D253E281087BBAF5 DFA63D3C97307E99 7EFC5CA40AECBD64 CE0C83233ED1B59F 7903F8F9A36561EA 51A0A3C05D88022A 93AAB3C5A729A991 9B60366334937BEC E5CC51268D297077 5D81AD15D229AF3C F1338D246FAFF980 EB97C600955D01E1 F838A47979043427 1FE6C6804B8C8017 5984089E964FD324 C55D8E708817D536 47F5910129D26508 C68A230929D64BFB DE9974A1AB012CEE 11C34DD68D1EC592 A77E8DE2340330C1 E6051A8DFE7FC407 8845500C3D9AAEFA 544EB0CDF563864B E5FC2CFFDB58E0E0 308474B8F2293505 08A15E121CC9EA30 BC69738BEC8D6E9C 25D4DF81B33A5BE6

Read the ciphertext. Strip whitespace: 592 hex characters = 296 bytes = 37 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209231457 (name+title). Key = MD5(password) = 99e95572c0c6f50187603f08031db5fc, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 9 GUIDs as hex (shown below).

Decrypted: GUID list

  1 d6b0c97b-9ae6-69a4-88fb-f8b804082251
  2 2eb833c7-22e3-1e54-ad68-a64468aa8775
  3 61fdbe89-cdb6-34c7-8248-84cdf3826f8a
  4 47331bd9-1d49-6af5-8445-4cb95e9d082d
  5 d6249320-ec54-2e81-9778-4591c2de1bd7
  6 1e9ebedc-7684-39be-8be0-6ddcc2a5bbd8
  7 165bd6f5-44c0-2728-9314-97ee70703c2e
  8 c9fd100f-2d63-75e1-a237-e6d5777f3f82
  9 bdfcc313-3c59-1067-a07f-d913ee0373b4

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 613623271. Exactly this sequence comes out of new Random(802).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 34 (seed 83,105,000): new Random(83105000), Next(8,64) per post. The RNG predicts N = 9; the post has N = 9 ✓. 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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