201210050503 10zh5v

explained decrypted filler

3DES(name+title) ECB, 10 GUIDs, seed 659

Metadata

Post ID: 10zh5v
Title: 201210050503 → 2012-10-05 05:03 on A858's clock
Posted (UTC): 2012-10-05 09:03:03
Timezone: UTC−4 · title 05:03 against posted 09:03 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(A858DE45F56D9BC9201210050503) = 0d1cbaf45cd568a5b1163e7534399dce (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 10
Filler GUID seed: new Random(659).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 219 · 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: 4 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

BD478635885AEC3C EBB814E6C2B5116A 3324A2446BAC0C63 0DE27CE1FABA4123 39734BB954AFB8D0 C534730A200DE2D5 ABAF197E4154A907 6E7C8D6FDB65383D BBE282EC1E2123C2 137CF4FB7D90A500 ED7C8E33510FD7E6 3DBDA6075026E5CF E219369263DB8D90 58C2B0E70256A1B0 B6B49A86B2BDE506 A31CEDA3C1C0E0C3 DC8AE384F1624EF9 BC4B24171A310407 CB12F869A911FD68 3F862AF8A46420F9 F8B54B692CBCBC78 13C86BFF36C56F58 068FD8037D9B4B56 AD5223483863A1BC 305552A1D9F2DDBC 32A865F24B2900B4 517EADF0BBE12CF3 1A5C44242C6A9730 C604D4BDB67E5E0B D89D2FEBC516DF31 6D68A8B71263C3C4 D0EA8495F5617B15 E3F104C3D70A1BCA 09EDB06577999BA9 D8C0682BF843836B 2A4B48C859863F90 C757E0328B4618F8 A6D836B28443A760 DA584501A475A3CF 8CF1820C393A2B0E 463FDCD9522E48AA

Read the ciphertext. Strip whitespace: 656 hex characters = 328 bytes = 41 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210050503 (name+title). Key = MD5(password) = 0d1cbaf45cd568a5b1163e7534399dce, 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 14d814f6-24a3-0ac9-8d88-d4b68b6532c7
  2 ddcba5c4-ad70-134b-a901-9d6c11ded146
  3 f554d0d8-e1a9-380e-92e6-598b43a2ea79
  4 de9cc003-92bd-164d-93a2-8a9c500bfae5
  5 1e484f52-b0da-66fb-9afe-1442d851149c
  6 c5ce8428-546f-4f6d-9bb9-f1c6e388fb5f
  7 7b555ab5-c93c-1b62-91d2-0e3ffdf27335
  8 ca709bb0-beb1-08b2-9e84-258f6e0a05b1
  9 c87bb9bc-4318-4ebe-83e3-1d5246d882ff
 10 a939a9d5-e7f4-2e63-9eb0-c86dfc213fc3

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 0131641042. Exactly this sequence comes out of new Random(659).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 219 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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