RC6-Block-Cipher

Implementation of RC6-w/r/b encryption and decryption in python. Values for w/r/b are 32/20/128

Specification

• Block size : 4 * 32 bit Registers = 128 bits

• Key size : 128 bits

• Rounds: 20

• Word Size: 32 bits

Features

• In cryptography, RC6 (Rivest Cipher 6) is a symmetric key block cipher derived from RC5.

• It was designed by Ron Rivest, Matt Robshaw, Ray Sidney, and Yiqun Lisa Yin

• It was designed to meet the requirements of the Advanced Encryption Standard (AES) competition.

• It is a proprietary algorithm, patented by RSA Security.

Functions

• encrypt.py and decrypt.py are used to encrypt and decrypt using user input or based on command line arguments

• rc6/helper.py contains helper functions

• rc6/key.py contains the data structure for the Key object

• rc6/ops.py contains the encrypt() and decrypt() functions as well as several functions that contain operations common to both

• rc6/block.py contains the data structure for a Block object

Example:

test code:
	import rc6

	testString = "This is a test string that is more than 16 chars and spans over multiple blocks"
	testKey = "abcdefghijklmnopqrstuvqxyz"
	res, str = rc6.encrypt(testString, testKey)
	print "Test String: %s, Key: %s" % (testString, testKey)
	res2, str2 = rc6.decrypt(str, testKey)
	print "len(testString): %d" % len(testString)
	print "len(str): %d" % len(str)
	print "len(str2): %d" % len(str2)
	print "Before: ", str
	print "After: ", str2

output:
	python test.py

	Test String: This is a test string that is more than 16 chars and spans over multiple blocks, Key: abcdefghijklmnopqrstuvqxyz
	len(testString): 79
	len(str1): 80
	len(str2): 80
	Before: ����ۋ��/�d�eu���T��.����P�Rw��UGϽB��Шő�<&s�D~4�t�Z�!�Ӑ!�L{B~ �
	After:  This is a test string that is more than 16 chars and spans over multiple blocks