Research this .  Read the whole article.  RSA Public Key Cryptosystem RSA, named after its creators—Ron Rivest, Adi Shamir, and Leonard Adleman—is one of the first asymmetric public-key encryption/decryption systems. It uses the properties of modular arithmetic of prime numbers to generate a public key that can be used for encryption and a private key for decryption. The encryption and decryption operations are also based in modular arithmetic. An overview of RSA is shown in Figure 8.