Can't it be achieved by this simple steps? Consider ur password is y. a) f(y, i) = a func that gets i'th character of a pass. y; b) hash(x) is ur hashing func; c) x0 = hash(y); d) concat(a, b) - concatination func; 1. x1 = hash(concat(f(y,1), x0)); 2. x2 = hash(concat(f(y,2)+x0)); . . etc

Store in DB id position hash user_id 1 0 x0 1 2 1 x1 1 3 2 x2 1