[W/K] :: public-key encryption

  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, 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)