I bought a programmable door lock and it has a feature called a “guiding code” which is a series of four random numbers that come up on the touch screen. It is supposed to prevent random number punching. I can disable the feature but I would like to know more about it. How does it work?
The mention a initial guiding code, but it does not sound exactly what you are talking about.
Basically it randomizes the number positions each time so someone watching can not get the number from the pattern or find out the digits through were the fingerprints are.
I googled around and I think it may be some numbers displayed that you have to punch in before your code. This would help even out the fingerprints and wear that may appear on the touchscreen.
It seems like it would be easier to randomize the keypad itself but I’ll bet people would find that more annoying.
I recall hearing a story about those 4 digit safes in hotel rooms.
A crooked employee (or anyone with access to the room) could do ‘something’ to all the keys and later return and see which keys showed a disturbance in the something. This would, of course, make it much easier to try the combinations.
It actually said they could rub their noses on each of the keys to leave an almost invisible grease mark.
So it’s a complete BS code that does nothing except even the wear on the keypad? That’s pretty cool. Maybe I will enable it again.
Thanks for the quick responses.
No, it may operate as securely as a “one time pad” encryption technique between entry control device and server… Of course the one time pad is communicated at some stage, or in the computers knowledge, so its not as secure as a on paper one time pad… and the entry control device (your keypad) must also show you the digits , so it has someway to determine what digit you were actually pressing… if the keypad was hacked then the hacker would know your pincode…
See the key pad computer shows you “4” but says to the server “he pressed position 9”. Well the keypad must know that “4” is in position 9 to show you “4” on the screen …
The server neccessarily knows your pincode, where else would be it stored…
I found the guiding code on page 32 of this file (pdf) it says that if it’s enabled, the lock will light up 4 random numbers on the pad, which you have to press before you can enter your code. It does not scramble the numbers.
I worked at an office with scramble pad security, and it’s not the sort of thing you want on your front door. The point of a scramble pad is to make sure someone watching you can’t figure out your code. These pads had a low angle of visibility, so you had to be right in front to see the numbers, then the scrambled numbers always took a while to find, pain in the neck, really.