201206261158 vn5r5

explained decrypted filler

3DES(name) ECB, 18 GUIDs, seed 556

Metadata

Post ID: vn5r5
Title: 201206261158 → 2012-06-26 11:58 on A858's clock
Posted (UTC): 2012-06-26 18:56:21
Timezone: UTC−7 · title 11:58 against posted 18:56 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,168 hex characters · 584 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: 18
Filler GUID seed: new Random(556).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 67 · predicted N = 18 ✓
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: 1,168 hex characters = 584 bytes = 73 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 18 GUIDs as hex (shown below).

Decrypted: GUID list

  1 52392109-3f77-107b-a50f-798d8495e1d6
  2 27dbd9fe-c22e-8100-b654-f387a164072e
  3 63602426-9e7f-33ad-81a1-bd403254537d
  4 9a5636c9-13a7-2b28-86e2-c429f3ebd6ec
  5 917d5d42-c8fc-26c0-99c6-8dcffeec86b9
  6 3c930c99-8ae2-49d9-b700-0a6312bf29cf
  7 8ad2c091-129e-01e8-b326-b03b90ed5c7b
  8 ff825dde-3fce-37fe-8d78-d4767473f3c0
  9 6a70b161-7332-6587-85dd-93fa104cb6ef
 10 01b3d65b-c8b2-2863-9a98-c114cd83e65b
 11 d87830aa-04fa-8e57-a128-3e36145cfaa9
 12 df2183f9-b769-40ab-aa14-4b72d1a996ab
 13 1ea28f1d-fd8f-73de-86ed-1543846c37d3
 14 757944e8-92f3-637e-b967-f9d0b1a2ced0
 15 566c9eeb-aa12-13ae-8256-4216d1455597
 16 42a09111-c0d3-28b0-8c9b-50e2e42d05bc
 17 08cdcafe-29e4-5ad1-b880-b9672303edc3
 18 550b70c8-849c-620d-8bd1-78044837df73

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 183224036284761256. Exactly this sequence comes out of new Random(556).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 67 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) per post. The RNG predicts N = 18; the post has N = 18 ✓. 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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