RSA is a publickey cryptosystem for both encryption and authentication? it was invented in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman [RSA78]. It works as follows: take two large primes, p and q, and find their product n = pq ? n is called the modulus. Choose a number, e, less than n and relatively prime to (p1)( q1), which means that e and (p1)( q1)
have no common factors except 1.
Find another number d such that (ed 1) is divisible by (p1)( q1).
The values e and d are called the public and private exponents, respectively. The public key is the pair (n,e)? the private key is (n,d). The factors p and q maybe kept with the private key, or destroyed.   _{Your Comment}