201210061424 111unq

explained decrypted filler

3DES(name+title) ECB, 20 GUIDs, seed 224

Metadata

Post ID: 111unq
Title: 201210061424 → 2012-10-06 14:24 on A858's clock
Posted (UTC): 2012-10-06 18:24:19
Timezone: UTC−4 · title 14:24 against posted 18:24 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210061424) = 3b0843dda8998ae07f88261f6fa1bcbc (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(224).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 319 · predicted N = 20 ✓
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: 2 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

25CA67475C7C2889 AE269CD090FEC3AC E5926222EAD0C281 C4833BCA7B8FC3DC 794A05500F2D13C5 EE904F157A1D9904 03F956D5C689520F A116121EDC2BEFEA 1D262ADFF96B870F 7E4C383C3E1A949B 6433672FFA60D705 277518BEE924375D AB8B79BE02BCA419 A7A1BB0EC48950E0 7A23D1DD5E0C6739 D114B5B7B3924C6B 8E3A514C5A6B90B1 147EAFA3E1532209 2B23F33F2B97BBBA A8C9B0C4C9552D6F C7DB4CB9D5C77DC2 DEE601994B74A789 7143B381FB37C949 B6E122BDFE6CAAC8 7FF4D9BA273342B5 1B5C690AFFC030C8 B14D4DC6FC6F16A7 F87F06BFC4CD0007 1E381A1923A91AC8 28317F757FE3E444 95C896E3712E6F23 F7D0EB88165E2804 C0680EEF95E77659 9C097F1814794706 76FBD662C5AA8A62 A22DC2DF6D78ECB3 E017DF7D2092CEB1 AA8680C6CA1B6DE5 AC465AC915592FC5 18AD30CBD1981159 0D25ED7F0BBD9484 A77A6C14DDB48B18 B47C1F83251611C1 CCEBEDC1CA34DF02 DB76EEF1268D518A 9051952B21BFCB0D 2C1C0A359C9B96EF 117A2D18271DD61F C571DC57744072AD 833EC6AF77875A7C 3E44D0AC96220677 359BDF44C3012A03 356FAE9637D1F448 E91C9E2DD99A06BF 231C14B4991456AB 1FDC36E23A7CDFCA B0CE911D29996418 FD48CD534F0EF256 12F32FC04DDF1690 CD1F2D625ACC6D31 2E698EC41AE00EEC 063FB7BB768210E0 3478D9D0681244EF A14D68810E399001 9C9AD88DBFC06EAA 1DBFAED826CCD8C9 D2092046A1D0ACCC 6358895CC547B21C 6391F05BBB2C46B8 B4AB248D3798F015 0B423A0F5ED2DD6F D8185BAAE7BB4946 D2FB5A59BAF2F6FE 5DC05AF3BD18D04C 2C7B1F1A19ECD495 516ADF7ADBCA32AD 8A477BB7ED686784 D7F4B6AC7C51901B A4383231C77FEE60 FB4DD290E0DDEC66 BCC82140923BD235

Read the ciphertext. Strip whitespace: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210061424 (name+title). Key = MD5(password) = 3b0843dda8998ae07f88261f6fa1bcbc, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 bda86ba2-991f-661f-b066-b2c5005b8bb9
  2 2f3b06a9-9b55-4b72-b084-e9a582a074a1
  3 190cd50a-f201-36ea-ad2c-6b462fda8093
  4 a75fe514-cd6b-31c7-9c8d-8bf689a87d17
  5 0730b20f-34cf-304c-af0c-0101cdde3510
  6 8c41f97d-ec3a-2a60-bb81-61fd9a23fd55
  7 f2d59143-0ea3-2f94-aa47-6ed6480969bb
  8 518e158c-296b-7582-8903-32b5152b682c
  9 35619daf-1287-6438-b46c-b82873ebcf1e
 10 9f92bf5c-07df-7926-af84-65d0913789bf
 11 835cf147-55da-2fa8-87c2-7b61048ca1e4
 12 f29e1c63-fef4-37f4-88d4-31111dc1e084
 13 cfc0669c-c043-5d6d-af5b-ed7490a08266
 14 d764c312-5c32-0677-9577-b72bcd0c92b3
 15 ea7844b9-4dae-6399-a400-85926485afc3
 16 35757929-4027-841e-b607-c088ae8ec11d
 17 2c892877-5836-023b-8efc-33c84b54f0ff
 18 81dcaa79-2769-7a6c-9dda-126e94a58cff
 19 659d95fd-3f51-6705-9686-8e0c6d31375c
 20 ac5c0df8-cdb2-01d5-8340-e20a14922216

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 64333227672350680760. Exactly this sequence comes out of new Random(224).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 319 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 20; the post has N = 20 ✓. 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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