RSA encryption
RSA encryption
(cryptography, algorithm)The RSA algorithm works as follows. Take two large prime numbers, p and q, and find their product n = pq; n is calledthe modulus. Choose a number, e, less than n and relatively prime to (p-1)(q-1), and find its reciprocal mod (p-1)(q-1),and call this d. Thus ed = 1 mod (p-1)(q-1); e and d arecalled the public and private exponents, respectively. Thepublic key is the pair (n, e); the private key is d. Thefactors p and q must be kept secret, or destroyed. It isdifficult (presumably) to obtain the private key d from thepublic key (n, e). If one could factor n into p and q,however, then one could obtain the private key d. Thus theentire security of RSA depends on the difficulty of factoring;an easy method for factoring products of large prime numberswould break RSA.
RSA FAQ.