hcrypto.engines
Class RailFenceEngine

java.lang.Object
  |
  +--hcrypto.cipher.CipherEngine
        |
        +--hcrypto.cipher.BlockCipher
              |
              +--hcrypto.engines.RailFenceEngine

public class RailFenceEngine

extends BlockCipher

Fields inherited from class hcrypto.cipher.BlockCipher

alphabet, blocksize, cipherAlphabet

Fields inherited from class hcrypto.cipher.CipherEngine

alphabetRangeOptions

Constructor Summary

RailFenceEngine()
Creates a RailFenceEngine and sets the alphabetRangeOptions instance variable to "111111", which translates to all six alphabet options for both the plaintext and ciphertext alphabets.

Method Summary

java.lang.String	addPadd(java.lang.String plain) AddPadd() This method receives a the plaintext string, with spaces removed from the engineEncode method.
java.lang.String	engineDecode(java.lang.String secret) DECODE This method takes ciphertext and places it into a 2 dimensional array, character by charcter.
protected java.lang.String	engineDecrypt(java.lang.String str) This method decrypts a String, returning a String.
java.lang.String	engineEncode(java.lang.String plain) This abstract method must be implemented in the subclass to perform basic encrypting step for a given cipher algorithm.
protected java.lang.String	engineEncrypt(java.lang.String str) This method encrypts a String, returning a String.
protected void	engineInit(HistoricalKey hKey) This abstract method must be implemented in the subclass to perform initializations required by a given cipher algorithm.

Methods inherited from class hcrypto.cipher.BlockCipher

decodeShift, encodeShift, engineDecryptFile, engineDecryptFile, engineEncryptFile, engineEncryptFile

Methods inherited from class hcrypto.cipher.CipherEngine

getAlphabetRangeOptions

Methods inherited from class java.lang.Object

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

Constructor Detail

RailFenceEngine

public RailFenceEngine()

Creates a RailFenceEngine and sets the alphabetRangeOptions instance variable to "111111", which translates to all six alphabet options for both the plaintext and ciphertext alphabets.

Method Detail

engineInit

protected void engineInit(HistoricalKey hKey)
                   throws java.lang.Exception

Description copied from class: BlockCipher

This abstract method must be implemented in the subclass to perform initializations required by a given cipher algorithm. Its parameter provides algorithm-specific information that is used to encrypt and decrypt. The key also provides a reference to the Alphabet that defines which plaintext characters are to be encrypted.

Overrides:

engineInit in class BlockCipher

Following copied from class: hcrypto.cipher.BlockCipher

Parameters:

key - an instance of a HistoricalKey subclass appropriate to the particular cipher algorithm

engineEncrypt

protected java.lang.String engineEncrypt(java.lang.String str)
                                  throws java.lang.Exception

Description copied from class: BlockCipher

This method encrypts a String, returning a String. It invokes the abstract method encode(String) which is implemented in an algorithm-specific way in the subclass.

Overrides:

engineEncrypt in class BlockCipher

Following copied from class: hcrypto.cipher.BlockCipher

Parameters:

s - the String to be encrypted

engineDecrypt

protected java.lang.String engineDecrypt(java.lang.String str)
                                  throws java.lang.Exception

Description copied from class: BlockCipher

This method decrypts a String, returning a String. It invokes the abstract method decode(String) which is implemented in an algorithm-specific way in the subclass.

Overrides:

engineDecrypt in class BlockCipher

Following copied from class: hcrypto.cipher.BlockCipher

Parameters:

s - the String to be encrypted

addPadd

public java.lang.String addPadd(java.lang.String plain)

AddPadd() This method receives a the plaintext string, with spaces removed from the engineEncode method. It adds padding letters. The amount of padding is determined by the key and the length of the message, using the mod function. If the rows of the railfence are even then another column of padding is added. If the rows are not even then enough letter of padding are added to complete the uneven rows. The padding letter is dertemined by the amount of padding needed. eg. 2 letter of padding would by b, and 3, c, etc. The padding letters are added appended to the end of the string and the string is then returned to the engineEncode method to be encrypted.

engineEncode

public java.lang.String engineEncode(java.lang.String plain)
                              throws java.lang.Exception

Description copied from class: BlockCipher

This abstract method must be implemented in the subclass to perform basic encrypting step for a given cipher algorithm.

Overrides:

engineEncode in class BlockCipher

engineDecode

public java.lang.String engineDecode(java.lang.String secret)

DECODE This method takes ciphertext and places it into a 2 dimensional array, character by charcter. The text is then read column by column into a String. The end of the String contains n number of padding letters that are removed. The resulting String is returned as the decoded text. Note that spaces have been removed and not replaced.

Overrides:

engineDecode in class BlockCipher