201207302358 xfj9g

explained decrypted filler

3DES(name+name) ECB, 19 GUIDs, seed 355

Metadata

Post ID: xfj9g
Title: 201207302358 → 2012-07-30 23:58 on A858's clock
Posted (UTC): 2012-07-31 03:55:40
Timezone: UTC−4 · title 23:58 against posted 03:55 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,232 hex characters · 616 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9A858DE45F56D9BC9) = 0dcc4bd9e114ebc42078977dc9125404 (name+name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 19
Filler GUID seed: new Random(355).Next(9) ✓ verified
Run: Run 20 (seed 267,961,078) (seed)
Draw: 2 · predicted N = 19 ✓
Machine boot: ambiguous: 2012-07-27 ~21:13 or F 06-14 12:54 (probable run, 6 posts) (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 4 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+namerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,232 hex characters = 616 bytes = 77 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9A858DE45F56D9BC9 (name+name). Key = MD5(password) = 0dcc4bd9e114ebc42078977dc9125404, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 19 GUIDs as hex (shown below).

Decrypted: GUID list

  1 31ad23dc-738f-1b74-ad76-96dba9e0d1f0
  2 1379616c-b68e-89cb-a643-a3c491982e74
  3 06838f52-26e9-860c-8e47-690b3f9d7f05
  4 32ab7b4a-7551-2969-beee-1f4033bc328e
  5 a44b530b-65ec-40b5-89f4-98ee01f6f809
  6 16b1118a-4307-7429-b1ab-70cc3354685e
  7 f55882f6-1e2c-8e57-bef7-9aebc7780c6f
  8 26e2ce9c-2117-4ecc-bdf2-38350176a8d8
  9 282a19c0-ca97-8ec1-a9de-354a4c34504a
 10 9b5389f5-51da-12ee-87fd-02c067d3ebab
 11 1c2cff76-6dca-7180-a887-3ab039d0ee9e
 12 fbb0853a-ecb8-5dc6-ae90-6c237f823593
 13 75e17324-7c79-642e-adf0-7f8a834e0c14
 14 a6494597-4a0d-104f-9358-44dc6a45b666
 15 f95ee379-276a-40d8-976f-043dfc258fdb
 16 4fa33795-2fe1-6be0-a7d0-b019166b6141
 17 90ec1445-33b0-063a-8333-b3b096a9586c
 18 614e35ef-c596-0796-be23-0bb4805472d1
 19 540a67fa-07b6-2919-9cf7-0b8bc8d59b8f

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 1882478481756146002. Exactly this sequence comes out of new Random(355).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 2 of Run 20 (seed 267,961,078): new Random(267961078), Next(8,64) per post. The RNG predicts N = 19; the post has N = 19 ✓. The seed is the machine's uptime in ms when the app started (boot ambiguous: 2012-07-27 ~21:13 or F 06-14 12:54 (probable run, 6 posts)).
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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