201210021000 10te02

explained decrypted filler

3DES(name+title) ECB, 10 GUIDs, seed 345

Metadata

Post ID: 10te02
Title: 201210021000 → 2012-10-02 10:00 on A858's clock
Posted (UTC): 2012-10-02 14:00:15
Timezone: UTC−4 · title 10:00 against posted 14:00 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 656 hex characters · 328 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210021000) = 88a235e218413cbea3b5888c481fad38 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 10
Filler GUID seed: new Random(345).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 18 · predicted N = 10 ✓
Machine boot: 2012-09-22 10:16–10:36 (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: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 656 hex characters = 328 bytes = 41 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210021000 (name+title). Key = MD5(password) = 88a235e218413cbea3b5888c481fad38, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 10 GUIDs as hex (shown below).

Decrypted: GUID list

  1 bf3e7f11-a1c6-8c24-ad59-811564fc0623
  2 3384c45e-9430-0378-b5c8-0b2748155f1c
  3 15aca10d-837a-8b51-a5fa-05c3dfd0b61f
  4 c50dd8bc-1eb1-17de-8a8e-0d2f4c608edc
  5 65c02c6c-1f8c-8367-a6cd-860d0ee826cb
  6 becf5556-7f38-0064-85ad-40a8ecfe7384
  7 e8ff7636-26ff-4edb-b55d-796987badb72
  8 820a0ac4-af34-4a3b-ac42-aa90399ac423
  9 8681fdad-bd9d-58c1-a1b8-9590c8b9b50b
 10 3dc20117-e907-4741-a68f-6db3fe3260da

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 8081804454. Exactly this sequence comes out of new Random(345).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 18 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 10; the post has N = 10 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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