201212050559 14a93k

explained decrypted filler

seed 999

Metadata

Post ID: 14a93k
Title: 201212050559 → 2012-12-05 05:59 on A858's clock
Posted (UTC): 2012-12-04 22:00:01
Timezone: UTC+8 · title 05:59 against posted 22:00 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 592 hex characters · 296 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201212050559) = a96c92a7ef5ec1e956d6aacfcecbc5aa (name+title)
GUIDs: 9
Filler GUID seed: new Random(999).Next(9) ✓ verified
Run: Run 39 (seed 1,106,402,812) (seed)
Draw: 49 · predicted N = 9 ✓
Machine boot: 2012-11-20 22:02–00:02 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 6 · 4
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 592 hex characters = 296 bytes = 37 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201212050559 (name+title). Key = MD5(password) = a96c92a7ef5ec1e956d6aacfcecbc5aa, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 9 GUIDs as hex (shown below).

Decrypted: GUID list

  1 5ce55a23-819d-51da-aad9-a7be4c970157
  2 99ff5bb3-712a-8830-98d3-29cbe122aeec
  3 9d35b514-36fc-02bc-87e8-72637d990a21
  4 48cd912d-67c5-795d-b8e0-ed61511f3727
  5 bb87f8c9-5dbd-21ed-8125-2ea1c5d3a053
  6 bf0d0feb-7971-5311-a0c7-f8b8bd89da93
  7 c8bf58d2-e63d-4e13-9afc-c4a18e53b33a
  8 e2863337-e9cb-59b5-b3b1-9b65acdabe21
  9 c050d2ab-8f87-5af2-a56d-1a71e36c1300

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 580725455. Exactly this sequence comes out of new Random(999).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 49 of Run 39 (seed 1,106,402,812): new Random(1106402812), Next(8,64) per post. The RNG predicts N = 9; the post has N = 9 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-11-20 22:02–00:02).
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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