201206290024 vsb5l

explained decrypted filler

3DES(name) ECB, 15 GUIDs, seed 570

Metadata

Post ID: vsb5l
Title: 201206290024 → 2012-06-29 00:24 on A858's clock
Posted (UTC): 2012-06-29 07:23:10
Timezone: UTC−7 · title 00:24 against posted 07:23 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(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 15
Filler GUID seed: new Random(570).Next(9) ✓ verified
Run: Run 9 (seed 449,725,219) (seed)
Draw: 17 · predicted N = 15 ✓
Machine boot: F 2012-05-15 19:12–19:12 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 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: 976 hex characters = 488 bytes = 61 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 15 GUIDs as hex (shown below).

Decrypted: GUID list

  1 30fce2b0-3b00-4605-96b8-b34a889cc0de
  2 9df3412d-92d3-06f3-8caa-0a5882ab39ec
  3 28cd8f89-fa59-1664-bb3e-9194b4881ffb
  4 d144a6a8-b859-188e-9a7c-3d414458a85d
  5 1687c980-f2a3-4a66-a416-805c17be15a6
  6 cf4534cf-0c26-6fc4-9297-dbc7ae22829a
  7 204d050d-9a06-2c11-8a07-2bd5ab951e84
  8 156f0e4d-ac8c-3a19-8381-37eb15d5cb7e
  9 9c3d40e1-1351-4906-b816-e9b4234415db
 10 400c220f-365f-43eb-b220-b4f984cac162
 11 ce507f36-c661-25dd-b3c8-b38b545ead90
 12 01540561-fbb1-402c-9036-20d85a5ff43c
 13 44f8f7f5-3272-48a8-86c4-5af8af817760
 14 1cd922d8-34a3-0308-b2ae-7cc3211f140a
 15 ed6a37ba-9d46-871a-9247-76110b3ef19b

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 401146234424408. Exactly this sequence comes out of new Random(570).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 17 of Run 9 (seed 449,725,219): new Random(449725219), 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 F 2012-05-15 19:12–19:12).
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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