27 ms·
The Haruhi problem reminds me of De Bruijn sequences, aka why I don't trust 5 button keyless car entry systems. Fords keypads do not have return keys, delays,
by ortusdux 8y ago
The Haruhi problem reminds me of De Bruijn sequences, aka why I don't trust 5 button keyless car entry systems. Fords keypads do not have return keys, delays, or attempt limits. A 3125 button sequence can guarantee you will unlock the door. It would take about 10-20 minutes for someone who has practiced to break in. Someone this year made a bot that did it in about 5 minutes.
https://en.wikipedia.org/wiki/De_Bruijn_sequence https://en.wikipedia.org/wiki/De_Bruijn_sequence
https://hackaday.com/2018/06/18/opening-a-ford-with-a-robot-and-the-de-bruijn-sequence/ https://hackaday.com/2018/06/18/opening-a-ford-with-a-robot-...
- latchkey 8y ago"de Bruijin sequence is a similar problem, but this problem has the additional constraint of being non-cyclical." [1] [1] http://mathsci.wikia.com/wiki/Talk:The_Haruhi_Problem/@comment-36964662-20181024143823/@comment-101.164.81.64-20181024145520?permalink=2075#comm-2075 http://mathsci.wikia.com/wiki/Talk:The_Haruhi_Problem/@comme...
- krackers 8y agoAdditionally de bruijin sequences are about generating all possible n-length strings from a fixed k-character set (where you can repeat characters). In this problem we only want to generate k-length permutations of a k-character set.
- strictnein 8y agoYou're worried about someone standing next to your car for 10-20 minutes pushing buttons and not messing up a 3125 number combo on a keypad with almost no tactile feedback?
- tspike 8y agoSurely a rock or other heavy blunt object would be more effective.
- codys 8y agoThe comment you're replying to contains: > Someone this year made a bot that did it in about 5 minutes. It's also the case that it's plausible one can interrupt & resume the sequence (at the cost of 4 extra button presses per interruption).
- strictnein 8y agoSure, but it's kind of silly. There are far, far simpler ways to get into a car than bringing a robot with you.
- pbhjpbhj 8y agoDo they give you on-going [presumably] secret access?
- sitkack 8y agoSo you are saying that keypad entry systems are vulnerable to meth addled mathematicians? https://www.reddit.com/r/math/comments/1jyp0a/how_much_amphetamineritalin_was_paul_erd%C5%91s_taking/ https://www.reddit.com/r/math/comments/1jyp0a/how_much_amphe...
- shittyadmin 8y agoYeah, this is nowhere near as bad as the proximity remote attacks where a simple amplifier is enough to trigger the key to open the door - or even to drive away with the car if you do a bit more serious engineering.
- wcunning 8y agoIf you read down in the comment thread on the Hackaday article, they make it clear that Fords after about 2002~2003 have an attempt limit. I happen to know that my '05 did, at a bare minimum. It's still deeply not secure, but nothing about a car really is... It's intended to make my life convenient and keep the honest people honest.
- CPLX 8y agoTwo problems with this plan though: 1) Even when you succeed you can't start the car. 2) Even given the best case scenario you end up with a Ford.
- rataata_jr 8y agoGT Mustang?