A858DE45F56D9BC9 archive

201307302100 1jcd5y

explained decrypted filler

seed 672

Metadata

Post ID
1jcd5y
Title
201307302100 → 2013-07-30 21:00 on A858's clock
Posted (UTC)
2013-07-30 12:00:56
Timezone
UTC+9 · title 21:00 against posted 12:00 UTC
Author
A858DE45F56D9BC9
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
2,064 hex characters · 1,032 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9201307302100) = bc3474e0e73c898818ad3ed42b7728c7 (name+title)
GUIDs
32
Filler GUID seed
new Random(672).Next(9) ✓ verified
Run
Run 49 (seed 822,652,546) (seed)
Draw
130 · predicted N = 32 ✓
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
0 · 1
Tags
automated (decryptable)2013Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

C00C69B435E6EBF1 F48E6F74527F44E9 0529D6514B062BB7 1E8891E64CFF3829 A34A3F6787202BDA 0FE1CEB2C3D833EB 137508B6C4A55F49 3DE2B2CA886C09F7 6FF7309426E6375F AA8864F7CBEEA69F 8728B39AA04D24FE 2DBE563A02B38C00 21FDABCCB99EA908 D3CB86B0DE5CF107 E3D56261BF316425 87500CC76357BFE8 BF7457CEBFF50213 DFF416FC01127DC0 958F96C002A60773 71D5BC7E574C9209 FBCE17E27B07C1C4 1A2D35F79501181B 4CDB273F2DCE05D2 573F83DBAA29ACC0 2CFE6FC1CF7B0DD5 78CE926DFAA306B8 6CA43A62E71B52F2 A1B26D57FDA8B217 F6D2FDD324FC686B C21CBA2C2D6AF2AF A9C41902A4FE063C 6586B7AA7BD36C52 440A6B4C577F1A1D 738E93125552F323 F720438BEC4F1DA8 B5159C94144F00ED 06CC6374EDEAA116 B474039C3138FFF3 B0929111D5378A66 E9EF95D1F4993746 F91540B362EEAC0B 2836E9BFB6D61359 F439861DA3657537 E6DE405AD6A59E7E 91EF9B63B5212C1A 29FBF960504BAB34 091E2329D9B20984 655DD096EBA368EF 04D9A2F33E8B169F 3C48FC3051088273 7D8BD93FFE2A97DE 538BB485317A6011 23000876FD68B484 D92097355611D646 63647B1885A56A81 E300EDC4B1AB9762 9486A427E4C7CE7C EF7A5A92575E8C44 7896DC4A0F2E155E A5799908F77D7D3B 18439912BB79CCF2 8D0B604F50C12591 587A08F0407E2CC2 14DC8CAEBDD1F202 A8B7B2B14ED0C271 B5CAB2912E10D7FB 2A7B75C134C57A8E CDFB59EE6B1255B6 7D236564B73E6D78 7F94489DFBF0C329 FBCEF1996414FE05 0D0569AB59C0213A 3664EB088BF288A8 702DE9798E23C694 48FFF92C4AED5FCB 2258BE05F240B483 BB16F4B061EC3C70 71F5103CD0F72813 433070D36FAF46C2 26A31C9DC7A208D6 350D8A93B52F178E DA06B0B5880E934C 66C9D0517AB5713E 24B3D7EAD85B5B90 774732D245F4FC71 DD0974DEE22B7481 B4DD92BF9C10AA46 B920C13A826A6156 29C1503A2EB29751 C403B50B0E78628B CE5B1CCCB2F2CC9C 5D4C9688DD099B9E 53697541A72DE043 441197DAA8CFC70B 2BFB5FCA1E34B229 ED3BC3E600718FB7 629ABB81D0E50CDF D3744D3C03580E0A 7E1E2FC0F03E0531 650D28EDD74BAC58 2630BC9705355D91 9CA34D7CF121DCFA 4AC4116D076D0971 AC331684F55D61C7 B3795E83636A3A17 71638D96101C6694 5482601653E194A7 FE19BB64291694FE A04F053CC29F3C0E F784C9557C1E89DE 7A21BCF7F59C0952 3C9D7B70F3323934 2F860559284385D3 D6007E1134C17CA1 03F101716FBEAD6D 6E4432F5AEE09261 3CD1B857DCA95FC6 A9D302E75AB6ED8B 1DADC2B95C2B5FB2 25B92921CA79C02C 3448EA7E5AC167B1 DDA7F8C950C54CF5 B186BF7FBB4AE65B 8303D9028E5F2E45 4C8A0BC962FC7F92 F3B13FFF08C1CA1B F81C185EA79F48C0 85429F89D8D05C96 E930142CC42E28FA
  • Read the ciphertext. Strip whitespace: 2,064 hex characters = 1,032 bytes = 129 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9201307302100 (name+title). Key = MD5(password) = bc3474e0e73c898818ad3ed42b7728c7, used as a two-key 3DES key.
  • Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 32 GUIDs as hex (shown below).

Decrypted: GUID list

  1 0cf0eb13-2a8c-7350-afe4-fa3a03b4b164
  2 04ddb132-a0d0-8431-b1ac-a90906df7c6f
  3 df4f1616-b592-46ce-8b58-1ceba1a5b4c2
  4 856712df-4c0b-86e6-845a-e2efad1641c2
  5 14cadc13-e768-533a-9fe3-d924c670ce9d
  6 5a91e4cf-52f3-7056-afb1-6819a7af619c
  7 7f2e054f-ec68-00f9-923d-9ddb08de2c62
  8 aeae8175-afce-52f4-93f3-cbbdb402cc1d
  9 481d3de7-ec82-10be-8de5-7988e8dbf097
 10 c57130c4-0082-0e13-acbe-773e02b84fde
 11 e238a5d8-4812-3aaf-a302-ad418dd018da
 12 55a25013-2d71-04ee-9ea2-608012cd3d86
 13 a7cf2c2a-d004-5eea-b14a-c389d3b08465
 14 99aeb094-744c-08a7-80c8-e6e00cefd812
 15 367c18df-3d4e-3b95-ab96-c38cb3b0a658
 16 f106d3be-55bc-66d7-85f1-37e93840946d
 17 6dc2a104-e333-3e6a-a109-d39bc6662a3b
 18 ee32209c-5e53-5e59-8834-cf16dce2dadd
 19 1dae07fb-bdd8-7d9f-990d-0bea3357eb3a
 20 5639e0dd-17e4-4b3b-9acc-f00b927b0494
 21 320b2fd2-6d52-070c-98a4-befc0769a05e
 22 d3e3a368-7841-6bc9-8742-647319dc8b11
 23 01f26794-c1fc-570d-9790-64293b8ded0f
 24 2e9ba2d5-2fab-7fed-b9d5-bbd9aa511950
 25 a00c79d0-4161-5813-ab66-61336ce8728e
 26 f0392c97-a75d-648c-9949-1b1e95d0a87f
 27 c5f8ef75-d040-675f-88b0-b5c69e6d6b48
 28 833be26b-9bb1-0560-8039-6565b4ab64ec
 29 728d4bf5-b2a2-1ee6-8ec6-e6474b76bc16
 30 001c77de-6ef1-2aab-a8e4-4b478ea96ba2
 31 c02c6d20-8b30-22cc-abb6-1d5ff7bc2cad
 32 ce09b16c-f505-4a2c-b345-09d34b79dd84

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 78485705103050363574065756601224. Exactly this sequence comes out of new Random(672).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.
  2. Explain the count. This post is draw 130 of Run 49 (seed 822,652,546): new Random(822652546), 4·Next(8,16) per post. The RNG predicts N = 32; the post has N = 32 ✓. The seed is the machine's uptime in ms when the app started (boot 2013-07-10 11:27–11:29).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs