201207020436 vw1d2

explained decrypted filler

seed 458

Metadata

Post ID: vw1d2
Title: 201207020436 → 2012-07-02 04:36 on A858's clock
Posted (UTC): 2012-07-01 19:34:58
Timezone: UTC+9 · title 04:36 against posted 19:34 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 592 hex characters · 296 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
GUIDs: 9
Filler GUID seed: new Random(458).Next(9) ✓ verified
Run: vvjmg (short)
Draw: 2 (assumed: numbered from the first post)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 4 · 1
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: 592 hex characters = 296 bytes = 37 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 9 GUIDs as hex (shown below).

Decrypted: GUID list

  1 eb515177-1f67-870a-9885-ed5505a6697b
  2 8fa211e3-6094-1b70-abed-93217b2e37c5
  3 6d6a3290-8ef1-818b-8117-ba5d8f2e1ee5
  4 28976b24-bec8-2a26-b5f8-5dd6fb626cef
  5 5557a0f8-d1f1-83b2-9afd-cd8ba97646c0
  6 5a7d2f9a-03a8-73d1-8ef6-abba4e762e53
  7 e4334bdd-800e-1872-8656-b89183673a3f
  8 c31a8117-8769-17f8-afdb-49ab9f926bb2
  9 e8ee87b5-e5a8-5d39-a1b9-0876d2edc021

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 818287115. Exactly this sequence comes out of new Random(458).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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