201207020036 vvqf7

explained decrypted filler

seed 877

Metadata

Post ID: vvqf7
Title: 201207020036 → 2012-07-02 00:36 on A858's clock
Posted (UTC): 2012-07-01 15:34:53
Timezone: UTC+9 · title 00:36 against posted 15:34 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 912 hex characters · 456 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
GUIDs: 14
Filler GUID seed: new Random(877).Next(9) ✓ verified
Run: vvjmg (short)
Draw: 1 (assumed: numbered from the first post)
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: namerun: short

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 912 hex characters = 456 bytes = 57 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 14 GUIDs as hex (shown below).

Decrypted: GUID list

  1 af456885-9165-8e21-a8ae-b9b07aa7c72e
  2 b3bb299d-3e9f-16d2-a761-4be9f5065213
  3 38a43aa4-8f13-7ef8-b46f-1c6ad6b14a29
  4 709a6da7-579f-6243-864f-79ac0ed9a919
  5 8e92509f-f1d3-1236-9d77-0b07bcc66c36
  6 7f7bc47a-4c64-848f-b9e6-3abfd948983c
  7 7e8eed7e-66e7-7cd3-b553-7e679b6f7dbb
  8 294052bb-6009-30c3-ba43-10b19b3f5f0f
  9 967fb4da-e54b-4331-9494-6626248d4e7a
 10 8a5023cd-57a3-6d5e-8691-78de8b070f0d
 11 015da158-9008-3ff9-836a-1ee115a7bad1
 12 c56eca6f-473f-14e6-b34d-d6b0e4645415
 13 670ed31c-8863-474f-bb42-b94497bdd03a
 14 7cf74997-835a-6029-9736-643e7e640df6

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 81761873463146. Exactly this sequence comes out of new Random(877).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. Grouped in vvjmg: 4 posts 4-hourly (zone +9) before run 10; undecidable: both June boots excluded under the 7-min launch rule, new-boot hits chance-level
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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