This trivial subclass of
Cipher implements an identity cipher that does not
transform plain text in any way. Unlike Cipher
objects returned by Cipher.getInstance( ), a
NullCipher must be created with the
NullCipher( ) constructor.
Figure 17-8. javax.crypto.NullCipher
public class
NullCipher extends Cipher {
// Public Constructors
public
NullCipher ( );
}