201206290025 vsb6b

explained decrypted filler

3DES(name) ECB, 14 GUIDs, seed 63

Metadata

Post ID: vsb6b
Title: 201206290025 → 2012-06-29 00:25 on A858's clock
Posted (UTC): 2012-06-29 07:23:33
Timezone: UTC−7 · title 00:25 against posted 07:23 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 912 hex characters · 456 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: 14
Filler GUID seed: new Random(63).Next(9) ✓ verified
Run: Run 9 (seed 449,725,219) (seed)
Draw: 23 · predicted N = 14 ✓
Machine boot: F 2012-05-15 19:12–19:12 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 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: 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 60eca82e-4e6b-55bc-93a5-4cbdad37f120
  2 e8d5f052-ebec-289e-a2e2-cd66be61b70f
  3 4ed405bc-8f4a-7d89-9cd1-43a173ea02c0
  4 d5500eda-9927-01d9-94a7-0e398d7217e3
  5 e451fced-5c8c-5f6f-b165-1e1cfde57e15
  6 2305663a-6b41-56a7-8b9a-747df95e36db
  7 d96f8860-fad4-1600-871e-e097bfb08339
  8 761f1eb0-723d-02e5-a780-871edf1f5984
  9 765d94ce-cf9b-63de-b3bf-422bed406e09
 10 e903fbd6-bae2-4ab8-b6bb-f8ac2e311c54
 11 2411fd0e-1569-6aa1-8a80-86dd84620e3f
 12 7477f21b-cb6b-5024-b4bb-5fb5423241d9
 13 da5b1e1b-ebfc-871e-b947-e51f4b22d1e2
 14 d46fd72c-8a0f-23c4-90d5-138e89b328b8

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 52705510646582. Exactly this sequence comes out of new Random(63).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 23 of Run 9 (seed 449,725,219): new Random(449725219), Next(8,64) per post. The RNG predicts N = 14; the post has N = 14 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 19:12–19:12).
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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