yes. i did it back in 6th grade (i.e. somewhere in 1997 probably) using Turbo Pascal without all this fancy/shmancy neural stuff. just 3 dimensional array, one

yes. i did it back in 6th grade (i.e. somewhere in 1997 probably) using Turbo Pascal without all this fancy/shmancy neural stuff. just 3 dimensional array, one plane for each user and get average time between key strokes. It was good enough to detect me, my mom, father and my friend. It also have downside - your patter will change overtime and if this is sole authentication measure - it will fail eventually. I would use it as fuzzy monitoring to detect stolen credentials instead.