201307200921 1io1ce

explained decrypted filler

seed 902

Metadata

Post ID: 1io1ce
Title: 201307200921 → 2013-07-20 09:21 on A858's clock
Posted (UTC): 2013-07-20 00:22:00
Timezone: UTC+9 · title 09:21 against posted 00:22 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(A858DE45F56D9BC9201307200921) = 12863b1ee4e47cc7c4f5fe93332e2c15 (name+title)
GUIDs: 44
Filler GUID seed: new Random(902).Next(9) ✓ verified
Run: Run 49 (seed 822,652,546) (seed)
Draw: 12 · predicted N = 44 ✓
Machine boot: 2013-07-10 11:27–11:29 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 0
Tags: automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

D36FB6D58FB2695D AA3175263BD0237B A1F0C0CB14548ACF 0B9AF4ED34E0C413 8681F48B8A0EACED 08B5BE74A3E71336 9300605901973EDD 3242925A78AA4E0A D31DFB029A1DC6FE FAE4F716EDEB3DA0 6992A21166E20637 915800255FC44D49 43A792EE18C7918F 6F072F3FA40103D2 B59121A2E12D96CF 5D3815CF02BEA388 C23FA9158B89A7A1 964BEDEC64F44D5E 98AD121C772433A3 11EA0C736ACAE4C5 C2888D2B2CBD5EC3 6700C958FEB7158A 3F2B3D20164FDA69 82199F889EBF0A93 346931F39054C927 F5C1936D2FB9824E 0725B6126CC219AE 7FB8FC9A66AA7E25 5468FF5ADFA87AFB 545970BF4B781E7D 66CEEDC595A7C339 B277399C2D764C1F D11AA1FA64C3F7B5 3952811C08BFD37A C3923F1EF1783EB8 9D2284CDD000AB55 AC3BC65A25F892EA 8EA7ADE441392B5F CD409802BD45B1E0 DF6E8998BFD4E0FA DF3E3A0E931F77B3 0BB05F5B856FBD04 04D6955FEC1F52ED 9643BC319BF321EA BB89FFE793F9AE7E 44E5425BFF25D656 B2048C247D8A2FF4 EA70EAD404252493 ADE3C5FB5B3D8775 8E4D5CD9838F305B B39EA7B82C2044CD BBCE1065CBCF3BC8 6B6B9E23B24785F8 7771B7441FC776BF BFF65A3C57CDEEFA 2A47526DD7B91068 86A8BBA213BC7A8F F04B7194F1455FC7 A73C867E3817E636 357A97DE8FBCF2B4 62B04E62972F1A31 DBBAC6C6F30481AB B6626B911EFED34A 63718F438C859951 BBF49C13E6688790 336161F824F0CB25 9EC1A51E8D3200D9 2809A7D6CA62F5AC 923750D8651E4810 B6CCF5A6189BB5AF 80447AD6C955DC1C 16B0BE7D983751D8 0A0A7DF037382DF1 18F85F9A34920EA5 3ADF71611FE88341 180C94A13077FC59 6B6EEE1CC9D9759B A40B89D1026541A2 3CB07B89C74B9CA5 A2CDED261C013E7C 6FEE5D8E083DA0CD 0E2D2C672AF3392A A546AC2815B975F3 ACF47BCCD7E986A4 484BF1672DCD7BAA 65E555505C7EAC15 606DAF7DEFB290A6 2869A3857105F510 D855EDCE4F877215 22EBDFDCB4C90072 47DC9975E985C266 BAD34C3140C8B2C4 B985B98A1F6FD32F 31CAAA73D7700E71 CB8F3A8EE7A1F77B 4263144A4901D186 985B0B86604D1DBC 3367DF6D0F36FC60 821CBC55769D1BE4 32A6D45A1E04B2EC B8FACBD62BC1ACAC F88A141608AC4648 2115C044F01197A5 D72CBB74E6EAC306 0E604CE8E8A0C224 F972835CCCECD3BC CF0F4D1712A3A3D2 02A3DB0636D28702 9C3705FC498E072C 7A5B23C42044EF48 C61B726955DB66C7 EA6E618E5B8BA4CD 10F71945E2944C16 38B4AD196D708EB1 BEBD0978D6FA531A 712CDF49FC0CB52B 03296DCAE31CCC9E A3AA2004C1FC6285 6E72395FE34CC5E5 3F9651A69F4C30DA 3E6D04944CE32499 44DAF6CF5A1CF014 EC5C1AED9FC6A55E 5A110234CE866E65 705D937BE2713D5F 1D66836EBBB2E3F5 8BC7905A7D8404D7 0C17047C70DA7F98 45C8061CEE98BFC4 2E61F7D76A1534B5 752F28D13CB44B5B 061B4C7DDA952FB6 B04305C3EF1078A3 753E21526AB3C7C9 148A25CD94363C47 87EA3C588EF28ECE 67245CCB1A29FFA4 ECAE0B76E0F010C4 6C83650D51C3CC15 A10E373C85298BE5 206E107439AF90EC B5DE9A4ABFCCD5CD F4E9D41C1C7DEC4B 74F178E5755F728D 64AC32D1457E0A37 D0AB7220E1C72928 89015D784ED7C839 2830E0CF6639B673 027EB085CBA8FE2C 35D42722CF82D9AB 87DC7DA623029361 DB2E485F935F88C5 348DF7D12E78EA3A FE6289D191C8ECBA 5DCDD4876F202A27 F2986AA5638D6023 5DE7DDCB81F1A2C2 D8B212605A952DA4 019EF9214B4CE891 D8F4B12E7CF4F3B6 8C3C89DFA637DA9D 6A9CB2AE5E98C4D0 A3D03E74700952A9 51220DEDCA4B9C0C 838AD4AC4479E97B 8BB9A92C0FF23F4C 31C60DFA6D06C2A2 BF6AEE7050638610 CAC2CF6767998F7C 3C3692E0AA42C2A1 5FC24A3E5D3940CB 889C138B0E4FCECB 72116C239274738C 81E450B4DA647AFF 242F27EAF1AEF92F C063643DE227A42A 8A01A3771DD1DDA8

Read the ciphertext. Strip whitespace: 2,832 hex characters = 1,416 bytes = 177 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201307200921 (name+title). Key = MD5(password) = 12863b1ee4e47cc7c4f5fe93332e2c15, 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 ac31dbf5-0cb9-89f3-ac1d-9bf3c44ef50e
  2 95aded0a-895b-4b88-8f65-61515adb6a4b
  3 19a37dd9-d10c-2661-bf6b-02cd4b3695a4
  4 84608e8c-b31f-09b2-98fb-252558fe52fa
  5 00bc948e-ee6b-4d6c-a97a-0fd909c8040b
  6 ccaabe5a-acec-7b34-863c-6da65770e040
  7 e4402345-e81e-0913-8ead-b00b81839f2d
  8 8b2719c8-0c6f-8791-9520-d6844c799e08
  9 b78becf0-12eb-5d30-bfc5-ea09cd0a05b9
 10 1a243cfd-abd6-7a48-b921-6bc146c1d756
 11 02b666d0-a863-7fec-8e7a-f8712bb26ae7
 12 7740188d-5d6d-62a3-9134-bc4911e4b37b
 13 dc7b2c5d-0583-65e7-b484-0932be5d768f
 14 c0bbb170-b1c6-610e-8450-3e37550bd352
 15 514f4b74-d66f-3a16-bb11-a47984e97193
 16 92418a31-e144-3e2f-a9d3-c43b0b2f5ec8
 17 149d0f53-140c-0b16-b77b-9564e810a779
 18 f399121b-d5d4-2b6e-8c6c-186fef702273
 19 54b8c992-4b39-07dc-8f2b-0f6e846af6ce
 20 cfa2b423-b321-5147-a7c1-0e5a84cfcf6a
 21 f2f5880c-9927-5267-a6ca-a584ee5978cd
 22 79990e5d-d557-10e3-8670-05db2ecc6502
 23 6f981315-fe9e-3386-950b-d14f94b06bc2
 24 e1a88c1f-8f0a-19d5-8ee7-2094fca539ff
 25 a40e8585-67a6-0401-ae57-8aadff1ebd1b
 26 b5bbd93b-fb57-6096-8782-279d6bebee12
 27 7092741f-e1e8-3a03-8f26-b84e038ee953
 28 70ced610-aef6-50be-ae6f-c0777e31b08c
 29 9f02c856-d4cd-646c-aa3d-85cff246e619
 30 63464874-94ad-4dc5-8bb8-9162b0febb39
 31 415db2ec-9312-1d2e-a92a-41ead9912fb4
 32 47f87706-c371-09a3-9218-e8891e721c7f
 33 b6bfbc13-795d-000c-98ae-afa19d6272c3
 34 b1d39603-928e-5f16-92df-e22a568efcc5
 35 96af8578-a3d0-51a3-b03f-c95172642ecc
 36 c917498e-f6af-794b-8b43-3f7711a089a9
 37 84a0d32d-ed13-1d19-9d3c-af05db4fef62
 38 0a8e5cfb-8ebe-08f7-b642-60077a825ac9
 39 c3f70ba8-4675-7aeb-ab62-40163f2d18ac
 40 1891255f-99e8-16f6-8c9c-7b5b04db9152
 41 1370c7c0-1f1a-8bd7-b56f-fd5ca1adae29
 42 6cb04bc5-3043-2a83-846f-81844997c18a
 43 d8323cdc-8e2e-193c-9670-f50938cc1983
 44 488eba40-7150-34a8-8cfd-ea327ac0ac8c

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 84204708577666330205513106356410055710718213. Exactly this sequence comes out of new Random(902).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 12 of Run 49 (seed 822,652,546): new Random(822652546), 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 2013-07-10 11:27–11:29).
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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