201210252353 123v3g

explained decrypted filler

3DES(name+title) ECB, 13 GUIDs, seed 909

Metadata

Post ID: 123v3g
Title: 201210252353 → 2012-10-25 23:53 on A858's clock
Posted (UTC): 2012-10-26 03:53:03
Timezone: UTC−4 · title 23:53 against posted 03:53 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 848 hex characters · 424 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210252353) = 751e3a0e902926376afbc623ed34815e (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 13
Filler GUID seed: new Random(909).Next(9) ✓ verified
Run: Run 38 (seed 1,045,884,937) (seed)
Draw: 10 · predicted N = 13 ✓
Machine boot: 2012-10-11 03:41–03:51 (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: 848 hex characters = 424 bytes = 53 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210252353 (name+title). Key = MD5(password) = 751e3a0e902926376afbc623ed34815e, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 13 GUIDs as hex (shown below).

Decrypted: GUID list

  1 86406043-b274-5b7c-83ee-92744671b8ef
  2 1c0c1a7e-9e67-4631-9760-02d2b47d4b22
  3 4a645894-28a1-1e5c-9990-caa72f947f88
  4 e3d5e816-7acf-5e85-9341-2cc257f447c9
  5 16c6aec4-3e0a-5194-9ec6-2acf40b8a542
  6 ff58906d-24f6-8326-b042-334b2141743e
  7 288b1448-0149-1c47-9975-7521d3ed3c6b
  8 1bb83480-005d-4011-838d-339c94015ce5
  9 b0a7ee2d-7d4b-38ec-a5d7-2aa2448c19f2
 10 afba20bd-b653-4e6a-ba5f-519221540878
 11 950c9964-4994-8db8-823e-1835e70dcdec
 12 8274d6d0-9d48-1829-a945-a9a2d5ce0dce
 13 dea55555-1bc3-458c-9d7e-6eb87f680965

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 5415581434814. Exactly this sequence comes out of new Random(909).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 10 of Run 38 (seed 1,045,884,937): new Random(1045884937), Next(8,64) per post. The RNG predicts N = 13; the post has N = 13 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-10-11 03:41–03:51).
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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