201206272111 vojde
explained decrypted filler
3DES(name) ECB, 13 GUIDs, seed 442
From the post to its content
As posted (encrypted)
906F485F248665CE 6A67CE70FD024DEA E5EF7E5ACB98DD09 77F49D8086C28C4D 910AE5E9CB037424 B5D8C6BE36B7D2F2 7C36639572280278 412138A364265DE0 069DB80DBA88D8F9 FCE4BC347949710D 2B4F4E68BF1AC246 DE37B7E430C2031F C6D3061BBE9513AA 942E0382861048E6 63DFAAB5E5C66159 4235987A6400A8D7 9CF97D551EE8D175 582990E90B2BEE1E B4F3AB11053F8054 A6B6B771115B85F0 F62E82721118136B A42161C209E42C46 BB39C59372FA10DE D45F4FA701770ECE 2B38E463B445DE7C B8A98C8401BA0A97 60F1B4F3DE974954 079A921B90732727 A12D5697787E650B 0EF09BADB1F73D90 9F3A43036D0D6BA1 A3CE8C929AC64CFC A1AF6BBFBC3B9651 3C0A5F0782DA0F4A 89DB6992E99D0220 B1993E70B4FA1DD3 27E4CC7DC26610FE 4B94D72643FCBB37 F47492AD0CA09FE3 7E7DBD70690277EA B077E468A14E683A A006D7220DEE43CC B13E9E3CF0713748 E9A04FBC4EE9A23A 71C96F8AF4ED16AB 826A227A7CEB644E 1B6BCE645558C405 0E52B7470205B631 BD5DB95685D5F76B E8385174E8F2D643 EFC05F11BCB046FC A71C2F13DD3E2FEC 5DACFFBA8FF64DBD
- Read the ciphertext. Strip whitespace: 848 hex characters = 424 bytes = 53 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 13 GUIDs as hex (shown below).
Decrypted: GUID list
1 16d52316-15ed-5dd3-9427-d6714f560d6f 2 1049b884-c76b-4baa-97f6-b07357d6b8ac 3 f52abac2-bce0-650d-802f-5cbc1635e139 4 d349a292-9652-842e-a668-0a4ff5fe9ecc 5 cbed5e43-f5c8-6cf8-8ddb-49369b1842dc 6 b83d1f14-7563-7def-a3c3-45bb35675229 7 43677fd0-3ddd-80e1-aa84-ed6ae31ec21c 8 ce7762f3-a216-15b8-b176-db5e4faa1bf4 9 f3f5ed96-e005-56b7-9654-a350cb01580a 10 c3c230c5-1c21-296e-b222-7556ee443562 11 72454c8e-8635-89a3-9f2f-67191f76067b 12 fdea4abd-3d91-435c-a8ef-f370da264837 13 f38c9770-ef65-4c84-af69-938b991f14d1
Explanation
- Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives
5468678152844. Exactly this sequence comes out ofnew Random(442).Next(9): the per-post millisecond seed of the mask generator. The other 30 hex digits of each GUID areGuid.NewGuid()output and carry no message. - Explain the count. This post is draw 18 of Run 7 (seed 629,367,141):
new Random(629367141), Next(8,24) per post. The RNG predicts N = 13; the post has N = 13 ✓. The seed is the machine's uptime in ms when the app started (boot F 2012-05-15 18:57–19:13). - Conclusion. Filler. The content is fully explained by the two RNGs.