A858DE45F56D9BC9 archive

201212060600 14cha8

explained decrypted filler

seed 838

Metadata

Post ID
14cha8
Title
201212060600 → 2012-12-06 06:00 on A858's clock
Posted (UTC)
2012-12-05 22:00:07
Timezone
UTC+8 · title 06:00 against posted 22:00 UTC
Author
[deleted]
Account
A858DE45F56D9BC9 main account
Subreddit
r/A858DE45F56D9BC9 the main subreddit
Category
F3 filler: 3DES(name/title) → GUID list, seed known
Size
2,000 hex characters · 1,000 bytes
Cipher
3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key
MD5(A858DE45F56D9BC9201212060600) = 3b3620ffce98e23dbbf4e7d23ce98131 (name+title)
GUIDs
31
Filler GUID seed
new Random(838).Next(9) ✓ verified
Run
Run 39 (seed 1,106,402,812) (seed)
Draw
61 · predicted N = 31 ✓
Machine boot
2012-11-20 22:02–00:02 (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)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

2C99DC23C44B13D9 BB433A048FCCAA1C 9D933FA08C6635B9 3A13B3831EE2989F F39E113D29098921 B04EE609B8A9DD8D AECFF4E31737BCEC 217DD76D6542C108 7746613F66AFB294 06820D6EC60930AD 6C0AA24D4CEEA51D D2A47BC3C5E976D3 93EA2A5AA862E54A 7ED9048523ED0AE3 1B6D96317D4EA7CD 1A225FC08A6703A7 37F34AE732F54F3D 6B2A527CC449052B BD22D3E5A44E3F9F 936C19310C51CB53 45909F5F72FD9FF3 113BAC6B10BED4B5 62D63E2BCD5EBA06 276B0157397DF838 6F1DA8E5E4FE54FB BF56B346754DDC62 33B3A86667275B94 AB63ED81A0572A4C 06277DFBB853691C CA013CA26919DD5B A219EF39093065CE 3318C3D98D11B337 DF9FB4BBFD9C172A 5C725499A680D19B 38103FD6B31D649C E42D003E8891B67E EBF5D4BDAC4283EA DA52BF5368AD438E E2D09136ADE685E7 EAD52CDDD57506A4 2F41540887B8366C 85E5F653D1D471D5 2C6CAD43FA622BE5 03CD94636C4E8C96 B8BD52EF9F65F538 443934F5CCAB2CCC 2B0CECA7C150DDC3 B89EE73C3977A966 B18D178ABEB4C233 6D89491C03742ED7 75A152DC5E0820B3 9C54F7D3BD1386E8 19E17E3A1DF8B886 D88E4B8755CBC650 432B338A0E0F6A26 FBA88FFB51AC3F12 4D49D9332455C88C 5FB4FE7D2A6C60E4 D3D87B81C2B00CF1 EAC4B42E53FFF98C F380DBF18A482C2D ECD16519D7E6767F 34D56727600D0D04 7DD863EAFD6BF0B3 83797DA9D12734A0 3FDEF6BD6E1A7C44 71491E0D45CE08BB 46320594BD83A719 AB8BE0739632D80D 415B736B53A4B89D 46E5199DF23913CD 79CA8DA4937FAD99 5B67540B47CA2042 71AF963813510BE8 4DE9CA9BEC85FA7A E1F4C8DE3C6CDA1D 880219FCC3C4F87E 73F49F324BB90D31 92E3FB8B110BAD81 934918A7DDFCD709 4DE1A77BEB0A971D C6137A951C4A246E FA98F1785ED9D1BA D78D153D7F830F47 F8E1D91A3E2CBB61 2CC92E6CED9A13C6 DC67CE7489405E58 6E6E6269A52251F3 CEDFCF781B814652 D532270EE21C6636 4AF310A437FA06C6 70089712A9A4B4D8 9476C5D17763A92C 16599ED862FB2C25 16165CB85CAE111A 349499D6D485671E 918FA8E65B3E9ABE 92ECB84C2C3B691B C621145C269D4685 2025170F182A006B ED8741319F0B172D 7651204C9BFFBDE0 7D39B6D5E7A98CB4 0BF5A45F4BBECB75 BA45923D56E6F620 24706DB07B0775A5 746985199EA39CB3 884A06BBA227D691 4ACA647E03D04621 43F2467A7FDB212D 41FD528FF8F321D0 5E7ED2830B56F11E 463A08BB518494BB CA9FF3A5FBEF8586 D2FE1A013C7A7CEA 2940AFD6DF22E1CA 97B92716CA65921C 17BB70147F31AABC F45E758A30D56B5D F54FCA14FB5DE13C 44835D1BAD4948D2 4FF3F0B45C5752EE CB717EEBA0B36E26 59D3AC659C32D56F 95D2E63A3ABF3855
  • Read the ciphertext. Strip whitespace: 2,000 hex characters = 1,000 bytes = 125 8-byte 3DES blocks.
  • Derive the key. Password = A858DE45F56D9BC9201212060600 (name+title). Key = MD5(password) = 3b3620ffce98e23dbbf4e7d23ce98131, used as a two-key 3DES key.
  • Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 31 GUIDs as hex (shown below).

Decrypted: GUID list

  1 c4fa707c-6604-48de-8a0b-e562b00346ac
  2 399cd895-75fc-62d3-9575-7234f6f24e9d
  3 eccee9e7-7db6-4e88-bd38-79c7935891a6
  4 3ec0959f-1b5a-3852-87d1-b630942b5e9b
  5 4c1f112e-660a-454e-9221-9db700279adc
  6 a25052cc-ae13-7052-9ddc-bf580dfc9c56
  7 4b6da2f3-688c-3584-a169-10dbfd6757bb
  8 fe6a19ae-3733-7b64-9a50-50eabc090516
  9 c206e342-b9ef-5af1-9780-7accc059cde1
 10 4f984121-75a7-2a2f-9b05-e46110c98723
 11 cb36898c-7b84-660a-8cac-9abed1252ba9
 12 8d546d85-5b9a-6dc3-b2ff-89b22df2c13c
 13 f48b4c6c-69cf-632b-92a8-4b759ca2bbd1
 14 c4a89e8e-7204-3223-b670-6c7b0bc14970
 15 4845c964-c624-5bab-bd08-d0944511f43c
 16 98219e0a-5f3f-3a0a-897e-defbbaca232b
 17 99b3efab-fd92-144c-a1b0-c3a81a49d82c
 18 07587b6c-666d-4a9b-9c28-7a3d4033a317
 19 07fdd8a1-d947-37ff-8039-9395ffa708d0
 20 886e1151-bdd3-7ba0-a872-28d4bebafd44
 21 945bc6b1-5d6e-1691-a08f-6aa83360f6af
 22 f0d32848-b582-3e5f-9066-8dce0cbbdbbe
 23 baca3e40-12c7-519a-88b5-2f654ec507d5
 24 9939a684-7209-70f8-a111-3c43b3266e76
 25 a5bc3e0e-a8ba-7f68-a353-074395ed6a4a
 26 f3ace0aa-f722-4b18-af52-f15d10075455
 27 6395ae59-bfdf-35cf-92c8-08982c032459
 28 3b0d1acb-4f65-80b4-b40b-9ca8a17f00e9
 29 1bd4f388-ce4b-0327-b6ec-8925b60934a2
 30 a77b93d8-880f-8dc6-9e5c-d758d3a6514c
 31 3310ef9d-0f50-5c09-9cc5-38308685e952

Explanation

  1. Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 4643473752666353143713577438085. Exactly this sequence comes out of new Random(838).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 61 of Run 39 (seed 1,106,402,812): new Random(1106402812), Next(8,64) per post. The RNG predicts N = 31; the post has N = 31 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-11-20 22:02–00:02).
  3. Conclusion. Filler. The content is fully explained by the two RNGs.

Related

Findings: Mask digit · Count RNG & runs