A858DE45F56D9BC9 archive

201210202200 11snw2

explained decrypted filler

seed 725

Metadata

Post ID
11snw2
Title
201210202200 → 2012-10-20 22:00 on A858's clock
Posted (UTC)
2012-10-20 13:00:06
Timezone
UTC+9 · title 22:00 against posted 13:00 UTC
Author
[deleted]
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
1,616 hex characters · 808 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9201210202200) = 99b0480520a518895578fec0addef768 (name+title)
GUIDs
25
Filler GUID seed
new Random(725).Next(9) ✓ verified
Run
Run 37 (seed 425,468,968) (seed)
Draw
14 · predicted N = 25 ✓
Machine boot
2012-10-10 14:48–22:48 (seed = uptime at app start)
Sources
community-archive, arctic-shift · body from community-archive
Links
Reddit · Arctic Shift · JSON
Score · comments
18 · 6
Tags
automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

85867F6351E609D1 6301C6A864CC6916 BEF61A5D42841E3B 6056CCDE7B372167 406A6B6A8DC28556 FBD3889C69BA5E07 494978A2C560D191 40588A8F2309072A 6889B8BECB073A69 63C615D29FDFE467 7527BD3AA610170C 0BC1232B06B06AD0 EF5445A141F26B5A 9161B23CCC7FC2C6 E867B77124EF6ECE 1D3B87854409F37E 2C6895D4D39AB047 18D1BBDE9F96DB63 937005C2D447C365 E24124E8E01F939A 51E3C466897839ED 77CDF43D5F14F9BC 7EBEBB026D5C2287 4FBD0DF3CD45F739 6AEE9D22A8ABF796 5736131906CBDE80 972EC315F676F1D9 B63A54A670567A4B 4DBD9D8BFD63EFD3 94218D37469438A2 27532B53F0C411C9 182F60B3BD29EE9E 9B9D53E5B39CFD11 BA4EE033633A7CEA BCB7FB41444577C2 BFB425A08414367C 27C951043BA1B222 8EED50DEFA9F6707 F3E38ABA00203206 042DFE0866E1150A 053B212F2C2F0232 C95FDE9FEBDFE641 4A3997472ACB58EB 89B31F7DE91C41DC AD04B210ABF6629A CE7F63230F829C29 2EF4B426DF49DDCF DECF267827718713 83E8CB3BA70101FC 4F160921967F7581 3E905ED6BEB40422 60F9E4ABF94A4E5D 572BEDFDAA9D6E27 3E7CBBEA7676F3E0 AD1C6B6F366E541F DDA4FB766C22F6F5 EB41B4FF3A80E3A0 F2CF09413279B798 2240099D8FF91822 A0788F9B6C7371D3 2A5FDFFEBB731E32 E1E8E2474DD37DA2 7FCD3DAF5CBD643C 2EE3F540A8A86010 8E76B7D1667F59B9 B0BDA10AD4C6AD14 52DFAEF462F6CB27 CF7BF16178D901B9 6930B21BD624CDED 0420BE7D3F050F81 C4CE0D22232981E3 21214B9CCE6355AB E2CBD45FB60B161E 9C67F28A7C3F8621 B44BD77FA2762919 F47EBAB26E542FC7 58ED05B650023089 07F6A67B7FE05C28 19CCFF13A5CFD87F 74A5C3FF17C37C6F 54CEE0EE4220ACFA 368DA3A8A7BE1120 0B18E73C36360CF5 6B2AD75FB1D9C554 DB1B9A9F09870601 6A2F408F25F63178 3299BC11130C7C4C BD61583E331D0011 11BB94CBB5A0A525 6114394A1DB08F30 921711B40D1CC5C9 8FB39A6B3396DBAB 948AE6040D64834E 538E17F6260158AF DFAF518671BAB2E6 AD28115F0C12E953 0546046E5538DD3E 681D315146DB43D6 363E7E1530D5276F 7F90817DACFE6191 A0B172A4889ADFB7
  • Read the ciphertext. Strip whitespace: 1,616 hex characters = 808 bytes = 101 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9201210202200 (name+title). Key = MD5(password) = 99b0480520a518895578fec0addef768, used as a two-key 3DES key.
  • Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 25 GUIDs as hex (shown below).

Decrypted: GUID list

  1 83cbca53-6ebe-471a-81e3-744228ca7c3f
  2 ff342b57-c846-4e43-a1fc-0d8a5bf64c71
  3 d997ae09-d7a3-4e9b-87f4-76aa27ff6ba3
  4 58124c9d-740d-230f-91e4-74cfe22099a8
  5 d14103da-4d3d-44a9-93bb-b601024f2ae5
  6 2f4d667b-3fb6-19f7-8c31-7aeb6f4fd9c7
  7 9edc55a4-9b9b-6230-8723-daef9bf4eb79
  8 bc70b4ca-ac41-10e9-a213-57f82444da80
  9 88be354b-99c6-655c-8024-8a7a41ce392d
 10 4da134f6-f2a1-5887-897a-89dc7bbae4af
 11 410a2d2c-6635-3d1c-b4e7-36bafec5f9c5
 12 bb9f0e67-abf3-4989-b08b-0d8ba0dad664
 13 949172a2-3d3a-014d-b46b-fcaba83c4e8a
 14 66ef7145-fae2-5586-af7c-cc7d4a50d9f5
 15 f0b2ca6f-550b-4048-96bd-ee5dccc9cf84
 16 195b4b8e-db43-7ac2-8dbf-3da5acac79b8
 17 aff778b3-08a0-5d69-9a5c-46d2df1fe8ea
 18 f3c5b96d-364a-4f21-920c-8784d0974b89
 19 d5a895fb-2a4e-2a75-b2ca-49f8a0cb0cc8
 20 01add189-9a18-0baa-bba8-ab71ea10df2a
 21 267006a6-2344-13dd-b6d6-6de9372e3d92
 22 5fc7e53c-48e6-6fd1-b81c-e176b76eaa9b
 23 b6d10f21-6c51-4db0-8990-41fcae7eff9e
 24 78816ee3-2d7c-2718-9fe1-bcd0bb4b2f41
 25 7d3d7b57-1679-6ff6-a2f6-a7badfa5d154

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 4442416165340547542016426. Exactly this sequence comes out of new Random(725).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 14 of Run 37 (seed 425,468,968): new Random(425468968), Next(8,64) per post. The RNG predicts N = 25; the post has N = 25 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-10-10 14:48–22:48).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs