encryption \encryption\ n.
   the process of converting messages in ordinary language, or
   other information into a secret coded form that cannot be
   interpreted without knowing the secret method for
   interpretation, called the key.

   Note: Encryption is used commonly to allow messages to be
         transmitted between parties at a distance without
         permitting others to read and understand the message.
         It is also used to make data more secure from possible
         discovery and uninterpretable by unauthorized people
         accessing the data. In order to read an encrypted
         message, a party normally requires knowledge of both
         the method of encryption and the secret key, which may
         be a single word or more complex sequence of
         characters. Until recently, transmission of such secret
         messages required that the key be transmitted secretly
         by some seecure and reliable method to the party
         receiving the message. More recently, a mathematical
         method was discovered to allow a party to publish an
         encoding key (the public key) which allows anyone to
         encode a message, but the message thus encoded can only
         be decoded by the person possessing a corresponding
         key, called the private key. This two-key system is
         called the public-key encryption method.

   Syn: encoding, coding, enciphering, ciphering, cyphering,
        writing in code.
        [WordNet 1.5]

public-key encryption
PKE
public-key cryptography

    (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>.

   See also knapsack problem.

   (1995-03-27)