201210161400 11k11h

explained decrypted filler

seed 714

Metadata

Post ID: 11k11h
Title: 201210161400 → 2012-10-16 14:00 on A858's clock
Posted (UTC): 2012-10-16 05:00:01
Timezone: UTC+9 · title 14:00 against posted 05:00 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(A858DE45F56D9BC9201210161400) = 71edc05e54c6258dcce85396f61f3e73 (name+title)
GUIDs: 21
Filler GUID seed: new Random(714).Next(9) ✓ verified
Run: Run 37 (seed 425,468,968) (seed)
Draw: 1 · predicted N = 21 ✓
Machine boot: 2012-10-10 14:48–22:48 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 9 · 2
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: 1,360 hex characters = 680 bytes = 85 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210161400 (name+title). Key = MD5(password) = 71edc05e54c6258dcce85396f61f3e73, 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 36e88687-36ed-6b31-b200-3c619368cfb2
  2 0e90bff1-43f5-2efa-b850-b2e1bfff94c0
  3 7e41fbff-66ba-76ac-b96f-714647cfe6b7
  4 6cfe915f-c6f3-80af-affb-fcab69d15cd8
  5 93a1b4e1-f18e-579e-80f2-c9620ae6f64c
  6 d2c27d38-4e66-4842-aa8c-83be46dc36d4
  7 7c664bdb-84d8-78f3-b1a6-966290094bf9
  8 1dabdd1c-c31f-5f8f-87d5-540e39fc6dbe
  9 23224488-72ca-2ae4-823b-186345c20d30
 10 d3e23474-d708-5f4e-a017-4dfd72694fdd
 11 e2cfd9ea-83ae-28d1-b4fc-7bc4322323ad
 12 b0170ae3-e991-8f3f-b0d8-cafd88e710fc
 13 568b1b3d-279a-4bf4-876d-55d1d9878a91
 14 20cdaef7-9544-84e2-b9f3-046d940a24d0
 15 851ef4a3-9be5-6e83-a624-6d55a4a5967d
 16 7e9a4604-1b56-8d3a-9c40-7ff680d3d386
 17 8f0a8b1d-28fb-8899-bcfa-73c50bd1d058
 18 1ff07684-a2ac-640e-b01e-bafddde9fd09
 19 a7fdd474-4d5d-06e9-bec7-755087c47a1f
 20 9150f5ee-483b-754b-8ecb-b81926695cf0
 21 673d8f1b-493f-64ba-8c49-6bfdd365bf1d

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 627854752528486886076. Exactly this sequence comes out of new Random(714).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 1 of Run 37 (seed 425,468,968): new Random(425468968), 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 2012-10-10 14:48–22:48).
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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