201211081545 12ujbj

explained decrypted filler

seed 79

Metadata

Post ID: 12ujbj
Title: 201211081545 → 2012-11-08 15:45 on A858's clock
Posted (UTC): 2012-11-08 07:45:10
Timezone: UTC+8 · title 15:45 against posted 07:45 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,424 hex characters · 712 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201211081545) = e96f355983f4ba73c8f73c0064d1dbd2 (name+title)
GUIDs: 22
Filler GUID seed: new Random(79).Next(9) ✓ verified
Run: Run 38 (seed 1,045,884,937) (seed)
Draw: 92 · predicted N = 22 ✓
Machine boot: 2012-10-11 03:41–03:51 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,424 hex characters = 712 bytes = 89 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201211081545 (name+title). Key = MD5(password) = e96f355983f4ba73c8f73c0064d1dbd2, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 22 GUIDs as hex (shown below).

Decrypted: GUID list

  1 d53cf4ac-0e1e-8ad6-ba05-667f08a494db
  2 0b0c9c39-8834-8fc0-89e4-63a71590159c
  3 84f57d53-979c-8b37-8d5d-81c507e520f1
  4 7d96c416-3715-3c07-a49d-2421198abe63
  5 bebd5e86-faf5-7763-b5d8-2445b28bd354
  6 82ef5997-c5ac-5e56-8d27-b1efc11c2db8
  7 d929890f-15e0-2297-adcf-43cf1ddeda97
  8 e7e420d5-b769-0b29-90e3-afbdcc5ff946
  9 fbd07c89-9375-6840-a6c5-b08152f08492
 10 68bbd079-9eab-329c-a606-0464fb496e0a
 11 4eac3e22-27a6-4019-beae-872f788c4ee9
 12 f78c5b0e-d6b2-1a56-b757-478453aef843
 13 e3937c43-9d0a-8b4b-bbcb-a8d61ad9627c
 14 0bd79edf-35bb-5e64-b9f1-db6ce173efe6
 15 ecd56e18-4962-2a36-893a-be81bdac8c7a
 16 4fc043ac-c37a-334c-88fe-1b283da5ed18
 17 75cb34b1-09ef-0c81-a8dc-c43ad037da71
 18 8e5cbfc0-07a9-8c46-833a-46b26c7ac4c7
 19 919a05a9-4f26-72cc-9bfb-ba3df890fc45
 20 7886eb26-849c-847c-a4c6-7254aa9affa3
 21 f7fcd8f2-542b-2f85-9376-261d5c845225
 22 21873d92-9b10-2bec-8e63-8f6c954dc3fd

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 8883752063418523087822. Exactly this sequence comes out of new Random(79).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 92 of Run 38 (seed 1,045,884,937): new Random(1045884937), Next(8,64) per post. The RNG predicts N = 22; the post has N = 22 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-10-11 03:41–03:51).
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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