201206261006 vmy7c

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 440

Metadata

Post ID: vmy7c
Title: 201206261006 → 2012-06-26 10:06 on A858's clock
Posted (UTC): 2012-06-26 17:04:27
Timezone: UTC−7 · title 10:06 against posted 17:04 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(440).Next(9) ✓ verified
Run: Run 2 (seed 1,054,905,639) (seed)
Draw: 21 · predicted N = 16 ✓
Machine boot: 2012-06-14 10:26–10:31 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 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 ea8c8255-78b4-5913-b271-26774e7f63a4
  2 94ffb8b9-aae6-81d7-bb56-dedb0621ef64
  3 b9505d07-6e25-2d2d-8a05-407f2f01d315
  4 0fb1ef65-b2af-47c3-98d0-285e34ad410a
  5 d50d259f-5216-7496-aaa2-0ebb17b86698
  6 205b1616-5a42-0334-a6be-3558528409ff
  7 a2135aa4-631c-0314-9b8b-dece98a707e5
  8 d22d9eab-8237-16f2-9843-f274a1aba4ac
  9 5a6ade3f-6d84-388b-8d98-8ed3ec14a425
 10 6a0aecf9-728d-4b86-98cc-8bdf5664bab2
 11 a541f20c-1d1a-4c2c-8bc0-587c8940e5ba
 12 f73552eb-ee8b-8e11-ba21-b1555b2c96d8
 13 7ae1f4ec-9c25-1a43-98ec-d988b907a704
 14 5278daa7-f953-3066-a2d5-47f94a9368d5
 15 da08dd26-51df-835b-a958-9d9a8288a66c
 16 285d7d3a-10fd-7796-805b-37c5f72b9324

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 5824700134481387. Exactly this sequence comes out of new Random(440).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 21 of Run 2 (seed 1,054,905,639): new Random(1054905639), Next(8,24) 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 2012-06-14 10:26–10:31).
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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