(PHP 4 >= 4.0.6, PHP 5)
openssl_public_decrypt — Decrypts data with public key
$data
   , string &$decrypted
   , mixed $key
   [, int $padding = OPENSSL_PKCS1_PADDING
  ] )
   openssl_public_decrypt() decrypts
   data that was previous encrypted via
   openssl_private_encrypt() and stores the result into
   decrypted.  
  
You can use this function e.g. to check if the message was written by the owner of the private key.
data
decrypted
key
       key must be the public key corresponding that
       was used to encrypt the data.  
      
padding
       padding can be one of
       OPENSSL_PKCS1_PADDING,
       OPENSSL_NO_PADDING.
      
   Returns TRUE on success or FALSE on failure.