201206270825 vnq4i

explained decrypted filler

3DES(name) ECB, 20 GUIDs, seed 374

Metadata

Post ID: vnq4i
Title: 201206270825 → 2012-06-27 08:25 on A858's clock
Posted (UTC): 2012-06-27 00:23:46
Timezone: UTC+8 · title 08:25 against posted 00:23 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(374).Next(9) ✓ verified
Run: Run 6 (seed 652,173,660) (seed)
Draw: 12 · predicted N = 20 ✓
Machine boot: F 2012-05-15 19:06–19:16 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: namerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,296 hex characters = 648 bytes = 81 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 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 2d2c33c0-0a6f-19b3-b731-513e19b7a3b3
  2 b7c2f540-3e2b-51b3-b5f8-1e164a962e64
  3 40026703-7adc-1836-8d39-af00c821ef85
  4 3704dfa1-0505-3a84-b78a-6c031a2c9991
  5 ffa08a1d-2a03-0b16-ad74-77751793b895
  6 2f9f468a-13c6-3a51-b762-59fe613c3852
  7 4d82930a-8cfe-4e89-acee-acc8cb1b2b5d
  8 0319b95d-6a00-06ad-9ca5-ce6965bb0eec
  9 9c80e43d-fbd8-2fd3-a3a5-bbc9222b6a6f
 10 f3c122bf-405d-1a56-822d-bba1d6830131
 11 89c24577-c561-7ab5-b543-ddb5e89444b4
 12 c905a6c7-4825-4f4c-8032-6beb3cba47f4
 13 b6a6b601-8bbf-6f1b-83c9-9f0a8d8c4b42
 14 8fbdcada-7ae2-0084-bd11-bfd85fd68796
 15 ac180b2a-bacb-66dd-b88f-24ab8ffd2860
 16 9c7ed736-f753-5508-bb88-3067d889ca6a
 17 f23c43b7-974e-0028-a91d-14f4a82fc364
 18 8b38ce2c-0847-744c-a2ac-0dc07fbce2a7
 19 a631692c-cb41-7740-88cf-85cb3338a8f1
 20 b1578b4e-3927-15e4-913f-af3faa3a2b62

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 15130340217460650771. Exactly this sequence comes out of new Random(374).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 12 of Run 6 (seed 652,173,660): new Random(652173660), Next(8,24) per post. The RNG predicts N = 20; the post has N = 20 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 19:06–19:16).
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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