201206291040 vsyjk

explained decrypted filler

seed 964

Metadata

Post ID: vsyjk
Title: 201206291040 → 2012-06-29 10:40 on A858's clock
Posted (UTC): 2012-06-29 17:39:05
Timezone: UTC−7 · title 10:40 against posted 17:39 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,040 hex characters · 520 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
GUIDs: 16
Filler GUID seed: new Random(964).Next(9) ✓ verified
Run: Run 9 (seed 449,725,219) (seed)
Draw: 36 · predicted N = 16 ✓
Machine boot: F 2012-05-15 19:12–19:12 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 7 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: namerun: seed

From the post to its content

As posted (encrypted)

17ED46FC365A8AAC 332C04DFBF410325 194AFCB2DEF54E74 143A458D600FD0D0 720E2055C8EE6B53 3CDB84B07246BF34 AFD5118AE14686DF B3CB5259EDAC2925 8167B09A72EFDE2A C865AA2D9705E587 BFAA7183779024F7 CE17A5F4BD37ABE8 213FB6C8CFA89E11 2039F6E6830CC7B7 D571B76C2B8D0EC8 2589C86AFB7BF81F 89A6ABFDED1DED92 B203A920F5557FBF 237349633BBFB994 1B0CDA39F9061FBC 8B0D83C7581F79D1 41411D1697B6F020 971DB0D07B001452 01F6D9D8F4844CA1 267234DD1E84AA3B DE8170A322C7730D CD769494BBFD0C88 5169107C60058C99 04B33D3511E517EF 1F777E5AA2850265 9077F6396B5B49C1 37109ABA2BDCEB23 7FD9FE760250FC74 E43F2A26987C9A10 831B5F367A3F9521 CB73B6EE2A47F19B 8FB308E984DF23A9 B4D6A33F57E60D7D 873AB3DAB6A313EB 771360464B76DCA8 38A1598BA81A13F9 F9FB4131DAC7B2D6 DD844958A88C8937 59B7B61181F39244 6D69475BB180BB68 374F2952656E2002 1C3D70213A002DCB 369693F11FF101D0 AC2B7C8CD46110A2 0BD8C60BA5D0A68E E1715D31C1874F50 5E198C0461D71846 50076321D689C6DF E441646CBB5F9F22 2067151F79A70AA5 9B1B8D6D4BE7E38E E0C6A126368A63F5 DB081FFE5D807090 BA42C497C5B57B7E 0306B387B1CD9343 A7CB5867C86C074B 2262F3A69A988D02 719158BFE4EAD23F 695201599494AD59 5DACFFBA8FF64DBD

Read the ciphertext. Strip whitespace: 1,040 hex characters = 520 bytes = 65 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 16 GUIDs as hex (shown below).

Decrypted: GUID list

  1 dbcb784c-ba4a-3968-b9ac-c41c4f1cff04
  2 8ff1dd9e-a3d1-6b03-9c87-af5a2b49ba47
  3 62c461ac-fe1a-5ee1-ba06-4b06f35ddee3
  4 20aac55a-4e68-20cd-b855-27e6dd0e0c9e
  5 aa540e31-a8e7-3641-9bdb-96cf06cfc970
  6 e357f148-bc7c-8416-8643-a7d058a95739
  7 bc90d1b3-5aaf-71fb-9b83-2ded0bc1be33
  8 c16fec79-41b1-08e0-afe0-82db5706cc72
  9 14f3c189-b5e9-2337-898f-3ba83bbc35bb
 10 e9cc709b-b494-65f1-aaab-94da56cce924
 11 62a6bc89-a128-4664-90a0-3b384ca05404
 12 c76fe2fa-c92a-0d00-9146-ec6522ea253b
 13 841d0097-d5a7-3683-980b-5e6b55445620
 14 ccf03538-7221-820d-8570-d564431d4926
 15 5b5d4697-7bd8-6492-b8e1-8461d3433778
 16 3e6f660e-45f5-06fb-a37f-2f5d5f07105e

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 3652387026403860. Exactly this sequence comes out of new Random(964).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 36 of Run 9 (seed 449,725,219): new Random(449725219), Next(8,64) per post. The RNG predicts N = 16; the post has N = 16 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 19:12–19:12).
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

Related