In Cryptography, algorithms like RSA largely rely on the practical difficulty of prime factorisation. Fast algorithms such as Eratosthenes’ prime sieve allow to identify very large prime numbers required for encryption.

In 1978 Tony Hoare, in his CSP paper, described Eratosthenes’ sieve in form of a pipeline of processes (aka daisy chain of filters).

A concurrent prime sieve implementation is available in Go: https://golang.org/s/prime-sieve

(The sieve of Eratosthenes can find all the primes up to N in time O(N log log N) unlike its competitors which run in linear time)

We have shown that the algorithm runs faster on FPGAs at least by an order of magnitude!

It is usual to develop a modified form of sieving of your own by chaining these filters. Have you ever thought of developing your own Encryption/Decryption application?