so what I'm thinking now is our DNA is constructed of combinations of just 4 nucleotides. So each of our chromosomes chould be expressed as a number to the base of 4.
Doing a simple XOR function between two samples would reveal the differences between two samples. If we were then do an AND comparison against a mask (for which bits are important) we could rapidly determine if the samples come from related individuals.
All we need now is a chromosome sequencing sensor on the front door to ensure that only members of the family are admitted. No more worrying about lost keys.
I interpreted as a new thread as it did not add to the on-going discussion, and DNA matching is serious programming, so imho it deserved a thread of its own. (Sorry I did not recognize the joke)
DNA matching does not need huge numbers but streams of millions of characters. Biggest problem in DNA matching is that between meaningful (identical) genes there is junk DNA from which the length differ from one strain to the other. So you cannot match it one to one, you have to adjust constantly.
KenF:
But sequencing the DNA, in itself, is not a casual task for a humble door lock.
How would you get the sample?
Prick your finger and smear the blood? ...ouch!
Spit on it?...yuk!
Other bodily samples that I won't go into here? ...even more yuk!
Pull out a hair and feed it in? What happens when your visitor is bald?
You'll still need to provide a sample, though, with all the problems I mentioned above. And the device will have to be thoroughly cleaned between samples to avoid cross-contamination and false readings. How are you going to do that? Windscreen wipers won't be good enough.