201210040141 10x8en

explained decrypted filler

3DES(name+title) ECB, 14 GUIDs, seed 764

Metadata

Post ID: 10x8en
Title: 201210040141 → 2012-10-04 01:41 on A858's clock
Posted (UTC): 2012-10-04 05:41:52
Timezone: UTC−4 · title 01:41 against posted 05:41 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 912 hex characters · 456 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210040141) = 628f7427c1e374d504eccef199941f7f (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 14
Filler GUID seed: new Random(764).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 137 · predicted N = 14 ✓
Machine boot: 2012-09-22 10:16–10:36 (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: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 912 hex characters = 456 bytes = 57 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210040141 (name+title). Key = MD5(password) = 628f7427c1e374d504eccef199941f7f, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 14 GUIDs as hex (shown below).

Decrypted: GUID list

  1 3febef97-5d55-7ac6-b624-926aaedca749
  2 11dbdba7-2a7c-86a2-9180-6def15f7397a
  3 7d7df12b-10e8-7ad2-9307-2605dc8b3be6
  4 4acd7213-520c-5fd7-bacd-c7a1d493bad0
  5 80fa3e4a-0e25-107a-b216-3cbf649e04b7
  6 84ef92fa-109e-1931-8129-a940a1518aab
  7 bc5af0b4-dc80-11e7-9dd3-450629797f97
  8 cb126361-9ef5-6a0f-9472-7e022b07d428
  9 e65dff66-82a8-4296-968b-8fd8f42ab74d
 10 d53c8ad9-6329-8055-b75b-91ac77552631
 11 6cdebf0a-deb2-1e8a-a7ab-ac27888b5910
 12 fff6b634-ea9c-82a4-97ca-59be394c775b
 13 f4e0a64a-d836-7ab9-9276-e6798787db7c
 14 db367e27-7a70-8bb8-9eed-d63271eb866c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 78751116481878. Exactly this sequence comes out of new Random(764).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 137 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 14; the post has N = 14 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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