201207022335 vylpl

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 968

Metadata

Post ID: vylpl
Title: 201207022335 → 2012-07-02 23:35 on A858's clock
Posted (UTC): 2012-07-03 03:33:41
Timezone: UTC−4 · title 23:35 against posted 03:33 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(968).Next(9) ✓ verified
Run: Run 10 (seed 38,548,093) (seed)
Draw: 6 · predicted N = 16 ✓
Machine boot: 2012-07-02 09:51–10:51 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 8 · 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 9a833e15-84df-302c-bbf2-736034c275cb
  2 eeacd8fe-e15a-7c8d-81bb-dab5b247f960
  3 27359e1a-b539-3e11-99b5-328ad65dbb5d
  4 cf4cfc99-ada1-18d9-9c0a-6eb85e63c141
  5 a0a823b4-f827-2147-874f-24fa7fd5c1b1
  6 bd9b6631-79f6-4f95-b941-d6a3b32d1e8c
  7 d0b44a78-adab-5bb0-81aa-46075b3436e4
  8 11541f31-b457-031f-abab-e43e924db5e4
  9 da3640d3-f858-65b7-bdd9-e297939f1d94
 10 b23d5f22-c0f6-2921-bbf8-4a6d909980f7
 11 6e0d37e2-3d74-4159-b616-6851c1b267f2
 12 54e2cfca-1282-1e84-aecc-bcfbd3779451
 13 7b98bec2-ddb0-0cb1-8dd6-283cc41ecbd8
 14 a824c314-e460-0708-837a-f079ee399dc3
 15 60d4af4e-8b26-4249-b69f-395e6c1f3ac2
 16 c0cc7234-fe0c-5ec3-a151-59ac08e54908

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3731245062410045. Exactly this sequence comes out of new Random(968).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 6 of Run 10 (seed 38,548,093): new Random(38548093), Next(8,64) 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 2012-07-02 09:51–10:51).
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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