201206260913 vmv17

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 880

Metadata

Post ID: vmv17
Title: 201206260913 → 2012-06-26 09:13 on A858's clock
Posted (UTC): 2012-06-26 16:12:11
Timezone: UTC−7 · title 09:13 against posted 16:12 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(880).Next(9) ✓ verified
Run: Run 2 (seed 1,054,905,639) (seed)
Draw: 9 · predicted N = 17 ✓
Machine boot: 2012-06-14 10:26–10:31 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 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 385cd1bc-f769-46c1-96ea-d9230b57a203
  2 6dbcec2f-503a-0a59-bddf-af14962fff6b
  3 cdddca05-ba8b-7852-b717-457e2b6d6e3e
  4 42e5b485-a38b-3218-992b-2a423337be6a
  5 c149064d-805a-414d-a880-b472800bda68
  6 1b256b65-9734-533b-b3a1-151b1c1161ae
  7 8c35c6de-d964-1aa8-90de-acf31e02107d
  8 dbe0ed48-186a-8cac-aea1-f02ebb9d5b83
  9 5ebfefb5-4d4e-7775-bb6f-b0eada191e50
 10 2371042f-1bf9-60bd-9ba5-12e09f1ba707
 11 e2a44af9-ba31-5069-a352-0a059b02efa3
 12 1afdf997-3e8c-4e74-8eb0-c1d779dfc5ec
 13 46da9a2a-0ada-5bd1-af3b-1364e87e7d3b
 14 4a5add17-056e-2ee7-8bee-580079d2ffdc
 15 7b277ee3-c5d4-89b9-a5c5-2a7a5be42993
 16 5bbee561-3d24-58ce-80bf-77f728f057ff
 17 1df17212-08df-7f6f-ac37-f28ffb473f5b

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 40734518765452857. Exactly this sequence comes out of new Random(880).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 9 of Run 2 (seed 1,054,905,639): new Random(1054905639), 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 10:26–10:31).
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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