Class StreamCipher

java.lang.Object

StreamCipher

All Implemented Interfaces:

Cipher

public class StreamCipher
extends java.lang.Object
implements Cipher

StreamCipher - implements a stream cipher that gets its stream by initializing a Random object with a given seed before encryption/decryption.

Constructor Summary

Constructors

Constructor and Description
StreamCipher(long seed) Constructor taking a pseudo-random number seed.

Method Summary

Modifier and Type	Method and Description
java.lang.String	decrypt(java.lang.String encryptedMessage) Return a one-time pad decryption of the given String encrypted message.
java.lang.String	encrypt(java.lang.String message) Return a stream cipher encryption of the given String message.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StreamCipher

public StreamCipher(long seed)

Constructor taking a pseudo-random number seed.

Parameters:

seed - pseudo-random number seed for stream cipher

Method Detail

encrypt

public java.lang.String encrypt(java.lang.String message)

Return a stream cipher encryption of the given String message. A Random object is created and its seed is set to the private seed of this StreamCipher object. For each successive character in the message, the encrypted message character is formed by the exclusive-or of that character with a random character formed by a Random call "nextInt(0x10000)".

Specified by:

encrypt in interface Cipher

Returns:

the encrypted message

decrypt

public java.lang.String decrypt(java.lang.String encryptedMessage)

Return a one-time pad decryption of the given String encrypted message. A Random object is created and its seed is set to the private seed of this StreamCipher object. For each successive character in the encrypted message, the decrypted message character is formed by the exclusive-or of that character with a random character formed by a Random call "nextInt(0x10000)".

Specified by:

decrypt in interface Cipher

Returns:

the decrypted message