201206271035 vnxnv

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 466

Metadata

Post ID: vnxnv
Title: 201206271035 → 2012-06-27 10:35 on A858's clock
Posted (UTC): 2012-06-27 02:34:06
Timezone: UTC+8 · title 10:35 against posted 02:34 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 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(466).Next(9) ✓ verified
Run: Run 6 (seed 652,173,660) (seed)
Draw: 25 · predicted N = 16 ✓
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: 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 f7a64bd9-4fdc-1469-8a9a-c5262031f261
  2 35f36baf-40c8-4861-82d1-8fa987b987aa
  3 01f93e5a-9837-4697-814d-2f94303aa3de
  4 54e9c9a8-c66f-03c0-bd7b-df0920220ac7
  5 cbf75164-0242-54ac-afc7-37bcfbb87cc2
  6 f6b32c1f-49ca-7d27-a992-a16a461465db
  7 a3372cca-f2db-6459-9107-1b59b6837806
  8 eae6fd56-9cfe-2786-ad0c-243bd36b064b
  9 168a10d8-130e-5c40-8e52-1e6f74f478d6
 10 3dd3e0c7-1e59-16eb-8a2b-6fa4beedd3e9
 11 46b1f172-d46d-5bdd-bbd9-18853ee198f6
 12 62f05f7c-fd7f-2efd-a924-eeeaeef5b08d
 13 7ac975eb-04cb-8d65-8529-a78e7bb80214
 14 2db5109c-6ae0-8f12-a07e-5c4ee599cca5
 15 c84089ae-b3a7-1fd0-aff7-f8d5c6528588
 16 0dbeb233-d92a-0c61-8af0-2dbf2b6095a8

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 1440576251528810. Exactly this sequence comes out of new Random(466).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 25 of Run 6 (seed 652,173,660): new Random(652173660), 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 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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