201206261140 vn4k6

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 583

Metadata

Post ID: vn4k6
Title: 201206261140 → 2012-06-26 11:40 on A858's clock
Posted (UTC): 2012-06-26 18:38:38
Timezone: UTC−7 · title 11:40 against posted 18:38 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,104 hex characters · 552 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: 17
Filler GUID seed: new Random(583).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 44 · predicted N = 17 ✓
Machine boot: 2012-06-14 10:25–10:26 (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: namerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,104 hex characters = 552 bytes = 69 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 17 GUIDs as hex (shown below).

Decrypted: GUID list

  1 1b57d55d-ae29-2df7-af5a-fbe2ac84f57a
  2 f39b988c-6335-7c3e-be28-38aed635ae96
  3 9b212b95-c1fe-2030-b40f-22b0d8b61fd4
  4 c8f513db-b83d-8017-9dd1-970aedbf13f3
  5 a0ce0bd5-fe7f-34df-b84b-6a199c948e41
  6 7c5a6893-70b8-0d82-9342-d193fabff004
  7 053fbe71-0b29-13ea-a790-e1a554584052
  8 bffec942-14fe-85d0-bf25-fa5a2fb72243
  9 21db737e-1c9e-0af5-ac79-a5f16156f734
 10 0791ec30-5697-2923-b9d3-6ae35c2307a0
 11 161fcf91-b2da-78e1-b6d4-81b69bcd0008
 12 aa24e24b-af11-518b-8c28-f3c21421c762
 13 2ac170f4-9e53-30f5-834e-59a50c65040b
 14 aa100539-1a6a-71da-b7c1-a9e3c6ecdfdd
 15 192426df-5f08-04d4-954c-4ea6a95bb1a2
 16 e96da4ce-999c-1cdc-bc45-a39b282fb3b0
 17 e171854c-e761-82b6-968c-6b6d77b95a0d

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 27283018027537018. Exactly this sequence comes out of new Random(583).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 44 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) per post. The RNG predicts N = 17; the post has N = 17 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-06-14 10:25–10:26).
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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