6 ms·
Pattern unlock has 9 spots, and you need to select at least 4. So the possible number of patterns is: 9!/5! + 9!/4! + 9!/3! + 9!/2! + 9!/1! + 9!/0! Which is j
by Plutor 13y ago
Pattern unlock has 9 spots, and you need to select at least 4. So the possible number of patterns is:
9!/5! + 9!/4! + 9!/3! + 9!/2! + 9!/1! + 9!/0!
Which is just 985,824. And you could certainly search the more likely combinations first -- people almost always select adjacent spots consecutively.
- milkshakes 13y agodoesn't that assume you can only select each pad once?
- jaredmcateer 13y agoYea and you can only select an adjacent spot so that also limits combinations.
- ZoF 13y agoYep, and the fact that the above calculation doesn't even allow for combinations greater than four... Overall not a reliable number :)
- woqe 13y agoYou can actually select spots not adjacent to the current one. Consider the "spots" labeled in rows from left to right as 1 2 3, 4 5 6, and 7 8 9. If I start at 1, I can go to 2, 4, 5, 6, and 8 directly. Also, if I have used all spots except 1 and 9, I can go to 1 then directly to 9.
- ZoF 13y agoYou can in fact only select each pad once.
- hfsktr 13y agoMy Galaxy S4 seems to only allow one direction for each node.
- deleted 13y ago[deleted]
- guard-of-terra 13y agoPattern unlock leaves a body fat trail on the screen that is trivial NOT to see & exploit.
- pigscantfly 13y agoExactly - if you hold my phone up to a light, you can easily see my unlock pattern in the fingerprints left on the screen.
- guard-of-terra 13y agoPattern unlock leaves a body fat trail on the screen that is trivial NOT to see & exploit.
- JoshTriplett 13y agoThat assumes you can go directly from any spot to any other spot, which you can't. Given a grid that looks like this: 123 456 789 you can't go directly from 1 to 3 unless 2 has been selected. I also don't think you can immediately backtrack, as in 213; you have to go 2513, for instance. With that in mind, I wrote a quick search: Adjacent only (can't go from 1 to 6 or 8) 1 9 2 40 3 160 4 496 5 1208 6 2240 7 2984 8 2384 9 784 total: 10305 total with length >= 4: 10096 Non-adjacent (knight-moves) allowed (can go from 1 to 6 or 8) 1 9 2 56 3 304 4 1400 5 5328 6 16032 7 35328 8 49536 9 32256 total: 140249 total with length >= 4: 139880 Pass through previous spots, no immediate backtracking (2513 but not 213) 1 9 2 56 3 304 4 1464 5 6136 6 21344 7 57184 8 105376 9 100928 total: 292801 total with length >= 4: 292432 Pass through previous spots, with immediate backtracking allowed (213) 1 9 2 56 3 320 4 1624 5 7152 6 26016 7 72912 8 140704 9 140704 total: 389497 total with length >= 4: 389112 So, I believe the correct number is 292432. For comparison, that's less secure than a 6-digit PIN, or a 4-lowercase-letter password. More importantly, though, if you're using an unlock pattern, you can't be using disk encryption, so anyone who has physical possession of your phone need not bother brute-forcing the unlock pattern.