201206261141 vn4mh

explained decrypted filler

3DES(name) ECB, 11 GUIDs, seed 698

Metadata

Post ID: vn4mh
Title: 201206261141 → 2012-06-26 11:41 on A858's clock
Posted (UTC): 2012-06-26 18:39:39
Timezone: UTC−7 · title 11:41 against posted 18:39 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 720 hex characters · 360 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: 11
Filler GUID seed: new Random(698).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 54 · predicted N = 11 ✓
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: 720 hex characters = 360 bytes = 45 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 11 GUIDs as hex (shown below).

Decrypted: GUID list

  1 e572cd8d-f209-3b36-a55c-1fd892a687ac
  2 4c85b3fd-1090-5c86-bdf7-f07c97375ea0
  3 c9b5d936-31b6-5f08-86d1-e050cc58e384
  4 68e40f7c-2553-409e-8e56-e74498f801cd
  5 f54de9dd-7851-3fdb-977e-299557171e3e
  6 afc966ae-423e-4290-b4bc-4513fac1a895
  7 d2aa9d52-4cfb-57d4-89a6-d9c46eddf687
  8 34c73f53-32d8-591c-8516-52c6074656fa
  9 7af0c5f2-0e26-24dc-9070-972eb6e827ce
 10 391e10b1-ac09-5a13-963f-3683ec0677f2
 11 f84e97e9-9c10-4938-85cd-7c1d7ae6842d

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 35543455254. Exactly this sequence comes out of new Random(698).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 54 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) per post. The RNG predicts N = 11; the post has N = 11 ✓. 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

Related