201206271206 vo2rt

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 974

Metadata

Post ID: vo2rt
Title: 201206271206 → 2012-06-27 12:06 on A858's clock
Posted (UTC): 2012-06-27 04:04:16
Timezone: UTC+8 · title 12:06 against posted 04:04 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(974).Next(9) ✓ verified
Run: Run 6 (seed 652,173,660) (seed)
Draw: 34 · predicted N = 17 ✓
Machine boot: F 2012-05-15 19:06–19:16 (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 3f2c8228-bc5c-5f54-8fae-55885ab0d786
  2 ece4b196-2bf3-5b87-ae36-58b650a23ada
  3 c073d016-0735-5678-a0b9-4e614e6aa9b9
  4 d2f53f1e-ec84-4e1f-97a9-2ecbae3114f7
  5 d4cfd821-bd1b-8f21-90d3-84b3a7c97fdd
  6 0f8d7be3-ad22-628b-b8a2-4e07f95f5817
  7 8f2b4c58-7a55-2b84-aeb1-6e7d5dc7e2d6
  8 27abc6a2-59a0-0df9-8f23-806155e82400
  9 df468925-661e-4421-8315-424be1c16d97
 10 ff70f732-8e2b-34e8-a61c-feea0924f351
 11 f6ddaa93-1bd4-7e89-a75f-0b338e6f4e71
 12 612e8fbd-9494-74d4-887b-0f9fb6a0157b
 13 ae89129a-a843-1938-8f1f-0bbdbd57c4cc
 14 e7fe9c7f-6d8b-12c6-96d5-6ab55772ac69
 15 9998aec4-a17e-6444-a7a1-e963f42ec210
 16 3bfe6130-8540-2f1a-b6d3-c54026b703e2
 17 b6a0d437-8cae-2052-92f3-1c129c141c10

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 55548620437711622. Exactly this sequence comes out of new Random(974).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 34 of Run 6 (seed 652,173,660): new Random(652173660), 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 F 2012-05-15 19:06–19:16).
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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