Answer:
1. For prime numbers of 31 and 43 and a seed of x0=7, what is next value in sequence of 49, 1068, 909, 1154, ...
Additional information:
The Blum Blum Shub (BBS) method is as pseudorandom number generator and was created by Lenore Blum, Manuel Blum and Michael Shub in 1968. It uses the form of: x[n+1]=x[n]^2 (mod M) and where x0 is a random seed. The value of M is equal to pq, and where p and q are prime numbers. Let's try a simple example in Python: >>> p=7 >>> q=11 >>> M=p*q >>> x0=5 >>> x1=(x0**2)%M >>> x2=(x1**2)%M >>> x3=(x2**2)%M >>> x4=(x3**2)%M >>> print (x1,x2,x3,x4) 25 9 4 16
Ans: 49