201206260827 vmsbh

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 63

Metadata

Post ID: vmsbh
Title: 201206260827 → 2012-06-26 08:27 on A858's clock
Posted (UTC): 2012-06-26 15:26:10
Timezone: UTC−7 · title 08:27 against posted 15:26 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,104 hex characters · 552 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: 17
Filler GUID seed: new Random(63).Next(9) ✓ verified
Run: Run 1 (seed 1,054,668,128) (seed)
Draw: 3 · predicted N = 17 ✓
Machine boot: 2012-06-14 10:27–10:27 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 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: 1,104 hex characters = 552 bytes = 69 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 17 GUIDs as hex (shown below).

Decrypted: GUID list

  1 a34c936d-28bb-51ac-93d0-90f1952a754e
  2 ce275b18-dd06-2531-bc5c-0a8911e45404
  3 95e8a1bd-a63c-7cab-bf10-c9a6b1158859
  4 855d1b12-f7a5-08ec-90b1-1b5d374405f7
  5 1fb39185-b765-5831-902f-c94b1e7a68ea
  6 a2fc695e-6a24-5647-8e54-d8b2a1a060de
  7 12ec587a-8964-1b37-80cc-4b8652364168
  8 2af1f267-4a3b-0b98-ae0a-0f718dc8b90e
  9 7fecfc3c-0452-6ec1-a7cc-edf0c068377e
 10 d3273c36-8df0-44bc-a087-634b79c5fbdf
 11 420728b3-cf34-685b-ab16-d058bb5d4429
 12 cf23625e-f158-51d5-ba0c-4032ade8e1bd
 13 4eeb1327-6075-86be-b75b-cb0c18188392
 14 763080db-ccb3-20a7-b428-2caa3c10d2cf
 15 605ba157-c869-0d9e-ab6e-a5d74e882ac9
 16 2ea3e3f1-3858-3153-8687-0deea40a69cc
 17 be361e20-2004-3d46-9f3d-504c3879081c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 52705510646582033. Exactly this sequence comes out of new Random(63).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 3 of Run 1 (seed 1,054,668,128): new Random(1054668128), Next(8,24) per post. The RNG predicts N = 17; the post has N = 17 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-06-14 10:27–10:27).
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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