(PKE, Or "public-key cryptography") An encryption scheme, introduced by Diffie and Hellman in 1976, where each person gets a pair of keys, called the public key and the private key. Each person' s public key is published while the private key is kept secret. Messages are encrypted using the intended recipient' s public key and can only be decrypted using his private key. This is often used in conjunction with a digital signature. The need for sender and receiver to share secret information (keys) via some secure channel is eliminated: all communications involve only public keys, and no private key is ever transmitted or shared. Public-key encryption can be used for authentication, confidentiality, integrity and non-repudiation. RSA encryption is an example of a public-key cryptosystem. {alt.security FAQ (http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/alt/security/top.html)}. See also knapsack problem. (1995-03-27)
