201304121531 1c84pg

explained decrypted filler

seed 20

Metadata

Post ID: 1c84pg
Title: 201304121531 → 2013-04-12 15:31 on A858's clock
Posted (UTC): 2013-04-12 19:31:59
Timezone: UTC−4 · title 15:31 against posted 19:31 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 2,832 hex characters · 1,416 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201304121531) = 2c5dd3add5bd0d4e401543bd8f30bbba (name+title)
GUIDs: 44
Filler GUID seed: new Random(20).Next(9) ✓ verified
Run: Run 45 (seed 51,450,859) (seed)
Draw: 5 · predicted N = 44 ✓
Machine boot: 2013-04-10 12:46–16:39 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 8 · 1
Tags: automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

DB75528DFD4C0374 2CEE2493F85B1710 B14FABFD7041A6D0 5176E43CF236F71E 94B828AA1C61EF1F 08AE1C8FC7AA3486 98C28AE227647794 06C63D6BADC40724 D1782388A04E134F 9B4EB26C5E171C1D 0471F123BE175848 90615910644FD965 56332FA640224118 2463EA120DE5BDCA 2C168131FB41D208 AF25A4E77C49F0F9 BBA3942FC691C780 B4F580324525F5CE 80164D9F9972902F E40314C0D2E22A38 D81A7C69CF849340 7296BEF61046CD95 298EC27C99C372B7 4785BF3BEB9A3802 575B3D79567B7439 EB2230D3D6831F49 78DA1BB49583BE74 ECFC26F5A2066F2E F98E9005F45F6BA9 193F3EBCA7F209D2 810EE6611E50FE2B 5EB6FBAF3BC4C772 1F08546B07207C43 577DEB6D497C51D3 50D4CBACC65DE3A3 955A0511017A644F 56AD11B72CBC79FD BAB4C5D197F2D813 7CE204FEB330DFB0 542B31968205984A 62BCEC864389ED01 48598BC783B92DF6 BE19A301165D1791 2D0C6F27274FBF74 82770D984216B014 1D76658E90B13EB6 62F6ADE48A1405C4 8B08F5102C787E7F 4D3F69FAAD8F6A24 5CF4DBCD345357A1 94EC8AE23A76004E 29EFAA3CAF46601F A709CCEE95CEAC26 482750AF6E010941 D5E6F7AA6EA1220C 8FD4F8174350368C 3A5F9CC3583D152B EE8501EFCEF861DC 6F215C74A68C5FF5 EEB2BC8A729DC36F 433471E7E8E02A5C 57161C96BB3041ED D9D91BC47D3D697A 4A7E5FB2558E26EF 4DFB2DD51A02BB2B 94B1049F7AF0A898 47EFB4698517C113 9C4BE3D765317C2C 9D3465FEA9B44921 0A2BB6FE49EC1D69 A0CFE31E1A50EEAE 7C9ECCDDDCE9BAFE 6A789DF41E719E40 45D5810AC6073D97 53E60EC74571A71D 89C857843C370FF0 682D1253A01D691E 112C04AD8B4AB3EF 87D975BF459E0184 3206E63DF1C28A85 E6CC50CC593688BA F246A89E01C8C286 10A4506440927BC1 60C43C1BDE82B01F 3C076FC977168394 D7237BF9BBE54F34 46C141B7536B187B ACAD815B360D8DF0 48FD189C35AD5F4E A17D3F9C665B622C 73CBF085239D8199 6EAFC8D2BD2E802E 8973BBAD04418E99 8EBC48FBA7FF2225 1E7AAF72972583D5 38FA87854F9A0F7F 238B75D32FE014CA 0F3785B7030108D3 1191EC3C876154B5 AC0A223C617AEF01 CCE8061A4315B01A D64F389FAC29CBC5 2E2E6E1EBCF3E9E9 878036A4CEC87B3E 3A44361DD901F628 5F2CABE4EA1D0535 4CF076BD47B34742 8869044877BBB70E B4F1945D082365E5 DDB59AA2A199FED5 48545E86DD0CC2BF A4715617F70D91A8 0A5EB8C7B6B32780 35E177C9278FF94E 6A8D73AEDC5FD085 DE4ED935683DDCFC 8EE2D393933CA3AF 0F2060A0838353D9 32CDEB0CA669B64B B2539FE8963CCCC5 B58C31C3EC3C490D 0B3526C9A2B49F5D D3B1A6E5F54EC80D FD6C3161B474FBE9 C5EFA84A8A58148C AA0CAB730C14E330 AA4CC88502D07F1B E21038DD4499F24A 6C8C782E6FA3C100 3E79A56451C2FA9B 7B6E8BF4D01425B3 829524C1F96D8D8E 23AD0A51EF6CB4A6 E986893A2C3B3C21 1DBF9EAAC8019316 650751E43FDB8E9E C109D22586B0CDEE BDB89C8B0D4E734B 2E48885D8F8D0ED6 696C071A2B27CFE1 C9D46ACC8BC1EA71 4C588862F5339CF2 28971AEE95158BA2 D1F3B10D0845B3A2 28FB4CF097976E08 1855489CCF52EEFB D2BCBB841E879902 D4E0BD8F0393022C 63BFEA1B3727D3E9 17EB0239E7A466A3 8CB3F286690AE60F FB3F20417690FB39 B47C6A2DBE39E130 AD4EE329167AEE09 A4B44E42104508D2 F64031FED5595061 9CD7678056B528A2 60583A796DD4D3FA CDCC29EC0DF6E189 96875A8D22B94719 4E4466C96B85B1C5 A1F36CC83969D9A8 5076FE0ADB298E47 509505DF26CFDB7B 0DF4AA0F82C6AE52 37E0C8306B03898C F8C18216320ABA09 62449014E49987E6 B1080451DD7D39EA 60C02630DF827CA5 BFB34C60A1FA4197 4DA18AA2DED998A8 4AFBE8F7C677E391 37C9AF06A765F5CD 841FEC2A22035CDA 9D872B137AAF9F77 65AE8CB56CD49A1F

Read the ciphertext. Strip whitespace: 2,832 hex characters = 1,416 bytes = 177 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201304121531 (name+title). Key = MD5(password) = 2c5dd3add5bd0d4e401543bd8f30bbba, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 44 GUIDs as hex (shown below).

Decrypted: GUID list

  1 f525a600-ccbc-1219-9a04-c01a59a0a501
  2 398736b5-a730-6a38-8cba-2961f71c71db
  3 071db008-17f1-6988-ac01-84e2813c9989
  4 e107a45e-3ec5-7c5d-960a-6e24cbc7e94e
  5 b49ad499-7aef-293c-8634-275e19db9462
  6 568aec8a-af13-043a-9d25-a057be3a149f
  7 8bfcf01e-bb12-7c27-867d-9eb81ce1d9b9
  8 796e9469-469e-4c57-84e3-82032147a8b8
  9 4aa100cc-4578-41c7-8021-9ff65ffe29ed
 10 dd173597-d679-5e15-b3b5-1f6b07b97d8e
 11 f243d1cf-861f-0452-b777-7e119e936287
 12 c408a1c3-3865-0f5c-add4-b77cd60fce6e
 13 df4be5af-cb38-3968-af43-e51557beb4c0
 14 cf9c160b-e303-7c01-b3e4-a311ff3cc737
 15 dc319e53-b189-87ef-bb10-680984a7f301
 16 b0c1608a-85a7-40e3-bb60-7a1c95c0d84b
 17 04bc9125-f093-2030-b524-b110d2db052d
 18 53d10631-92c1-36dd-9325-bb470e54c2f8
 19 c2be3fc7-ff6b-12ad-96b6-8bd979a1f094
 20 c07af931-9616-0509-8584-c609080ce948
 21 abefad8e-da76-4f6f-be60-2a1ac56e854c
 22 9fbdabf7-ae9c-6855-806b-adf494459b6d
 23 0691e344-eb27-3d39-8ba7-ba09cf4250d9
 24 f1891f27-672a-09ad-a9bf-34d440c51abb
 25 17c3e062-4812-51c1-a259-271429a55b69
 26 e0f47cac-cbfa-3d84-95aa-c2d69322525c
 27 049ed968-fb30-194e-b653-966e4d120910
 28 c6f1917d-d00c-0143-94cc-772a3bf7d9cd
 29 22acd0fc-a76e-050a-a607-8c092dfa8e2e
 30 e0c7942b-16dc-1346-a528-befb50b2aeaf
 31 ad58cc21-0793-5c9e-9b49-c951bea17a74
 32 af7c8858-ea4a-669c-abc7-8fa7df3eb256
 33 b39f8075-8b54-3774-8c92-d67229594db7
 34 ea683e53-e570-4a77-9a1a-c9c50eed191e
 35 a9ae4a53-a682-5d45-9ea0-f2c1effe2886
 36 704e31b4-05d8-573b-9b79-cf644d1b3cc7
 37 e1437608-ca31-579c-9d70-8e46cef430e0
 38 4ca7063e-4557-0543-b559-8317a142462c
 39 e8416646-1e4f-63d4-86a6-058a0e0d5f80
 40 37dc5bdb-0f2c-26d2-b2ea-2299fec514f8
 41 688591d5-fddf-78d2-a97a-8ed50372a567
 42 840f1304-ce50-2a1c-8467-bb9854624d5f
 43 61b1af4a-82cb-545c-bb55-1304f0fcd610
 44 0c3e9845-efda-4908-85b8-ac806e558447

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 16672074450037842310463053100156345550627254. Exactly this sequence comes out of new Random(20).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 5 of Run 45 (seed 51,450,859): new Random(51450859), 4·Next(8,16) per post. The RNG predicts N = 44; the post has N = 44 ✓. The seed is the machine's uptime in ms when the app started (boot 2013-04-10 12:46–16:39).
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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