201210260127 123zu1

explained decrypted filler

3DES(name+title) ECB, 15 GUIDs, seed 863

Metadata

Post ID: 123zu1
Title: 201210260127 → 2012-10-26 01:27 on A858's clock
Posted (UTC): 2012-10-26 05:27:42
Timezone: UTC−4 · title 01:27 against posted 05:27 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 976 hex characters · 488 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210260127) = 6035755d7a0aad044430e2d7ba6675cd (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 15
Filler GUID seed: new Random(863).Next(9) ✓ verified
Run: Run 38 (seed 1,045,884,937) (seed)
Draw: 57 · predicted N = 15 ✓
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 · 1
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: 976 hex characters = 488 bytes = 61 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210260127 (name+title). Key = MD5(password) = 6035755d7a0aad044430e2d7ba6675cd, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 15 GUIDs as hex (shown below).

Decrypted: GUID list

  1 3c15a113-21c9-5cb7-a710-5493decf18e3
  2 a84c8e92-15bf-0eaa-895a-60c689a8f7be
  3 25304320-95a5-8620-a84e-ed276d8d97d0
  4 72114111-4ad5-698c-9729-84d8225ac89c
  5 5047132d-cba8-797c-8570-3cf534a4eac2
  6 5765e4cb-526c-6624-bd6e-66dce0249e26
  7 95e69340-4d6e-541e-b823-84539947e7e7
  8 595ba8a1-ef3a-3f73-ac6e-bee3343ff50e
  9 e70a12f2-ddfe-6f61-ab9b-0f867a261cc0
 10 08b02a6e-5550-4c57-a3eb-968bb50d2318
 11 0beebe92-1870-0b94-b23c-710148d552b8
 12 3352c998-1c59-2873-8c50-a09622410a1d
 13 f2c063fe-f98b-8651-9804-16deb1a9d2e8
 14 7649da66-2767-4853-a29a-d74b02d5e125
 15 29df7fcf-08c8-06cc-907b-a4d3cad0e007

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 508676536402840. Exactly this sequence comes out of new Random(863).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 57 of Run 38 (seed 1,045,884,937): new Random(1045884937), Next(8,64) per post. The RNG predicts N = 15; the post has N = 15 ✓. 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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