201210070544 112z7u

explained decrypted filler

3DES(name+title) ECB, 16 GUIDs, seed 776

Metadata

Post ID: 112z7u
Title: 201210070544 → 2012-10-07 05:44 on A858's clock
Posted (UTC): 2012-10-07 09:44:57
Timezone: UTC−4 · title 05:44 against posted 09:44 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,040 hex characters · 520 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210070544) = 10f371a62ede4e893f32e56202d70932 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(776).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 365 · predicted N = 16 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 0 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210070544 (name+title). Key = MD5(password) = 10f371a62ede4e893f32e56202d70932, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 d0f16e25-96e5-192f-b840-f6ea8b2e2506
  2 c1a6b73f-80c1-403f-9a8f-7aee3c05bdf1
  3 41016983-dd94-16e7-9c09-14eaf8b0a94c
  4 d3b6630b-5f03-1d87-8c2f-e35048653c75
  5 6fc8fc73-4783-58a1-94c2-7b73ac182c70
  6 7a9bb3e2-b6c9-61b0-9ea3-04b6beab78c8
  7 a1f28483-1428-58e2-b0c4-a8dcfa37c765
  8 378817ea-986e-6045-9787-6f02ba52cc0d
  9 b31b1c6b-a638-8810-b590-7af3c54b7de7
 10 db1c1143-25f3-3d79-9c65-e5557902a168
 11 da8c387e-3c50-8ba3-91f5-649f4fcd10fb
 12 e7792d7b-9289-2bb6-8e54-b908a028c816
 13 2579e3e7-442a-01c3-ae04-48f80177ee36
 14 ab926add-52b3-1225-8335-9e3a21a98e54
 15 25819443-e95f-11f3-95bd-f18ed62c34a3
 16 b5d0ad38-a6ad-598e-a9d8-de6e8dd537f3

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 1411565683820115. Exactly this sequence comes out of new Random(776).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 365 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 16; the post has N = 16 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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