201206260843 vmt7q

explained decrypted filler

3DES(name) ECB, 16 GUIDs, seed 692

Metadata

Post ID: vmt7q
Title: 201206260843 → 2012-06-26 08:43 on A858's clock
Posted (UTC): 2012-06-26 15:41:44
Timezone: UTC−7 · title 08:43 against posted 15:41 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,040 hex characters · 520 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: 16
Filler GUID seed: new Random(692).Next(9) ✓ verified
Run: Run 2 (seed 1,054,905,639) (seed)
Draw: 2 · predicted N = 16 ✓
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: 1,040 hex characters = 520 bytes = 65 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 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 a76820d3-2890-266c-8db0-c051ee962d67
  2 22b46c92-2f0f-7305-a778-6fb4f6bb6673
  3 6c3e47a3-998c-43c9-9044-8da33a37ec13
  4 e61cdab3-b1c6-29c1-b9de-ffdba9bcc977
  5 a949cf74-d97e-5174-a85d-c2816b13970a
  6 7f6bd375-d4c8-2733-96ea-fa5f54382956
  7 e1ececf3-5471-8451-b807-3bf9c1db91e1
  8 ac2f90bb-b48d-52f2-8e27-1d77201e1b66
  9 14ed6102-c96f-51df-9926-97b8564d63d5
 10 3ad47a2f-e0b3-429d-8031-b0bc2e68fd31
 11 9ca1c461-e3ac-045a-949b-0ee075b00d8d
 12 fd864542-2016-64e4-91b0-2790cc7d6e4d
 13 18073b6a-c61d-3fb7-a94e-6f52e7481dc2
 14 cff69fde-efc1-4433-ab6f-cbee1c278430
 15 d3729344-25a3-38ba-bba5-02e6b92b456f
 16 e4e88a3c-19ab-1600-91a8-5f2ae56cab61

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 2742528554063431. Exactly this sequence comes out of new Random(692).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 2 (seed 1,054,905,639): new Random(1054905639), Next(8,24) per post. The RNG predicts N = 16; the post has N = 16 ✓. 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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