201210080825 114upq

explained decrypted filler

3DES(name+title) ECB, 21 GUIDs, seed 926

Metadata

Post ID: 114upq
Title: 201210080825 → 2012-10-08 08:25 on A858's clock
Posted (UTC): 2012-10-08 12:25:59
Timezone: UTC−4 · title 08:25 against posted 12:25 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,360 hex characters · 680 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210080825) = 20a5a99f7fea084633d51a9a8e6b2730 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 21
Filler GUID seed: new Random(926).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 445 · predicted N = 21 ✓
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: 0 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

4E3BC5FF765CBFA6 AA90A3D4FAD8736C 834219F6E37EA944 B81D00FE04DC56E8 EDAFE01195AA5059 D2C4FE270ED5CFBC 2CBF3ADF84A25661 C855583106AC2358 4382710E17CD5187 3C34BD8623044196 010890578379EAE8 4D049EFF8A0C7301 36793B66CCC8FFCD B7F38D02049E61CA 591859E222A4ED42 A282A3A765D206A1 CFCF035EE460ABAF 94876C90FBBA646C 18EFBAE93F1511D9 9276B57D554A5A40 943860452C4748CE C6AFBAA6136E2848 54607497B2F13737 D974257B9563585F ABC9F3785EE2C977 AE814CEE546A080C 01390691803D76CD 0F3E7DBA669BA20E A27F5AAA243217AD 36CF2CBDFDC8C559 19620FC9038327E6 19CC73D6543835D4 7443A8FAA2C32704 8AB3B3C6E6DE2425 6155C6DA609D33F2 53E7AEF801C64BC3 95C51FA111214DB0 1CFF40D476789353 4843FD72F4EF7014 AB1AFD8170951262 D76499AB52E02039 88274F0EF0577E74 8915B58743335B3D 2053AC0C7B83DEEC 180BB78D989768FC EB910EA504F61FEF 0AB31173F48DAF6A 6B1D9CAD08E784A3 70D5F4F721498D21 2C25180469D23F69 05AAAB79D4EC0DBA 7758E0EDC8D23CB1 129C84C6A4D9DF8E 7FFB45865E1700C7 E8EABD4760327D9F 1AFEB6F65FE51B1A 229A50EEFC571D14 596FF30E07B7C12D 9A8BD1CB119689AC 14D4BE5B0E24AA02 89A362CBD9D08D8B 5DD9064D8CCE68A4 5ADA68822DCC47D8 1B2E9FBF197AA722 E7010749E1FB5A62 B7EFE807727CA0E8 74D79CBC0781307D 2A2FC0B0B9863F4D F60DEE08A3761F68 63AD0F91F962059F 576B48021777D35B 4D05242611430CB5 03E244A3FBF674FA 77727E90179F2CD0 75E0110FE4A37BFB BA292CB83FDB8E37 534436012BF74333 89C21F012941054D CE4A2042B81049E5 C5CA060AB660D182 847385824E8F4388 A8EC15C6E1B313CC EFB3802A8109360F 83D1DA454564C585 1EF32E62B1D244E6

Read the ciphertext. Strip whitespace: 1,360 hex characters = 680 bytes = 85 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210080825 (name+title). Key = MD5(password) = 20a5a99f7fea084633d51a9a8e6b2730, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 21 GUIDs as hex (shown below).

Decrypted: GUID list

  1 f53b5656-71b9-49a1-aabe-e05dcbaf5da6
  2 5e8702cc-76c3-4935-b44e-021abf6451ef
  3 b4dd2e55-f194-0458-bc31-848d332f5610
  4 d1983065-2df9-1d3e-9cae-a37b95920e50
  5 b4850f0d-151c-28a6-98e6-7b40de0253ac
  6 fb192f5b-a0fc-7430-bc68-75deb7995d27
  7 83a506a9-e3ee-797d-b2a6-83772d3e834a
  8 d8535b0e-2097-01a8-a91b-0bd2dca599ce
  9 11698ba5-161c-4324-9d6e-17db3b642a21
 10 84af8838-9770-6a96-a82a-6eb54d1c8b46
 11 ebf116c6-28a3-404d-923c-0168b5cbbae6
 12 975b8e69-06ba-3c27-9348-5a9326a4d5ad
 13 59b47cd2-ddcf-14bc-bf44-ec898026d57a
 14 8cc99127-0002-2850-a5f5-36d1409445a1
 15 e3c5f619-396c-10a9-8d55-301debbda306
 16 ca1b8e46-62a0-3058-93b8-532aaaec44f8
 17 9313f039-a02c-117c-8fc0-6f3813b410f6
 18 e3861104-215e-10eb-a149-b1c82ff08056
 19 0625be09-91f4-6eb9-8862-017f9c6ae6b9
 20 7ac4455c-9e2c-7d22-ae7c-c1faf16ad9ff
 21 0e3bc046-0ca7-7be9-a0cd-97defa63d7af

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 440127704643121311677. Exactly this sequence comes out of new Random(926).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 445 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 21; the post has N = 21 ✓. 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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