Dumb question

[Jeff2017]

On the securicode keyless entry keypad, how does it differentiate between a 1 and 2 or a 3 and 4, etc.? The keypad pairs the numbers into 1/2, 3/4, 5/6, 7/8, 9/0. Is it timing based? It is probably obvious but is escaping me for some reason. TIA

 

[Jeff2017]

Never mind. I guess I answered my own question. It doesn't differentiate between the paired numbers. Strange way to do it but I guess it provides enough combinations make it unlikely for someone to break the code.