201206261101 vn1v7

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 555

Metadata

Post ID: vn1v7
Title: 201206261101 → 2012-06-26 11:01 on A858's clock
Posted (UTC): 2012-06-26 17:59:46
Timezone: UTC−7 · title 11:01 against posted 17:59 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(555).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 12 · 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 5096986b-4b7d-63bf-8d06-8891d29e1d05
  2 7c660214-c1c2-59f9-adb0-dc9c7084380a
  3 f182ee25-44bc-67ad-a135-c2b44bc89151
  4 3273c5d0-4c91-06a0-a0ba-f85f3a2b61e6
  5 6c66ca6c-0a2c-7e17-a80c-9dd761e3e786
  6 a9e569ee-8a60-5831-8b78-c4c961d1f3c9
  7 28475e39-8404-58e9-bff4-3f9c76498397
  8 f5829832-3655-739b-ace8-9e34382913aa
  9 d0833f17-6c7f-5d01-882a-7ab537a0a631
 10 44c9db23-660c-8681-a0ed-716bda419b65
 11 e12c8689-3567-11de-8b7b-7d8c85d9567a
 12 dfd1adc6-bae2-678e-9cc7-0483d63bdf7c
 13 c607f756-a7bb-1929-ad4f-eeef0394d61a
 14 e42cf302-9b8b-115a-9885-490507d9b371
 15 2cb5bb99-430f-44cb-b381-3b58883ad923
 16 b4642ebf-557a-56f6-93e9-7a8b9c54b5e3
 17 099a0e7f-a913-1ec8-a5e2-887ecb2e9ed9

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 65607557581611451. Exactly this sequence comes out of new Random(555).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 12 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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