201206261141 vn4nr

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 436

Metadata

Post ID: vn4nr
Title: 201206261141 → 2012-06-26 11:41 on A858's clock
Posted (UTC): 2012-06-26 18:40:03
Timezone: UTC−7 · title 11:41 against posted 18:40 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(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 16
Filler GUID seed: new Random(436).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 58 · predicted N = 16 ✓
Machine boot: 2012-06-14 10:25–10:26 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 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: 1,040 hex characters = 520 bytes = 65 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 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 31e1739f-485c-41d7-b735-6628ddf488e8
  2 5be5b3b8-73ba-6884-8c99-d1bb9cf93381
  3 56e09ccd-9aa7-412e-be57-9e86eb547491
  4 6f00d511-4702-59b6-8578-2b04ae860215
  5 9f9b311b-c0bb-052f-abb7-6c160e4f3194
  6 3084f36a-1bad-52a1-842e-775b28a6c482
  7 18eb86c3-2c9c-2f40-a914-e949a76b8f64
  8 cfd3fd86-9102-1ebf-98a7-7dad74074a9a
  9 c2688da1-713c-8bbc-8b6e-fefdedbca3c8
 10 87e85d74-8c0a-0c74-bc4d-551980d2735f
 11 50f989d3-f74c-45e1-9988-6daf8fddfe49
 12 27bedb69-5ce2-7d7f-a07d-f2fce7c44a62
 13 75ad2ecf-3485-3f03-9cea-3201ebac1aff
 14 d618a5f3-9bdf-2073-a680-cf7152608fb5
 15 1ba162a6-4c03-1ca9-adc5-247eab4b96c6
 16 79755c7b-4632-279a-b9f1-ddc20461c7e2

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 4645052180473212. Exactly this sequence comes out of new Random(436).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 58 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) 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 2012-06-14 10:25–10:26).
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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