Notes on Reference Citations - Version 2.70, by Dr. Herong Yang
Attacks on Encryption Schemes
'CipherDES.java - A Java Implementation of DES' tutorial was cited in a BCS thesis at University of Liverpool in 2005.
The CipherDES.java - A Java Implementation of DES tutorial was cited in a BCS thesis at University of Liverpool in 2005. Note that my Geocities site has been moved to herongyang.com now.
Subject: Attacks on Encryption Schemes Date: Mar 31, 2005 Source: University of Liverpool Author: Benjamin Nickolls Attacks on Encryption Schemes Supervised by Dr Paul Sant Honours project submitted to the Department of Computer Science for BCS degree in (BSc) Computer Science. Ownership of this report remains with the University of Liverpool. Acknowledgements I would like to acknowledge the support of Dr. Paul Sant throughout the course of this study. His help and occasional prodding kept the project moving in the face of all adversity. I would also like to acknowledge the contribution made by Dr. Herong Yang. Approval for the use of his copy written code enabled the implementation of the Reduced-Block DES algorithm possible. Abstract In today's world of electronic communication secure transmission of data is a necessity. This dissertation offers a critical appreciation of modern day cryptosystems and the security that they can or can not provide. A discussion of cryptography and cryptanalysis provides the basis for a practical demonstration of two cryptanalytic attacks: An implementation of the RSA public key system is used to illustrate an attack developed by Michael Weiner exploiting a class of weak public keys containing information on the corresponding decryption exponent. This technique utilises the continued fraction algorithm operating in O(n) time with respect the size of the modulus. A sixteen-bit, private key, block cipher similar to that of the DEA is also presented for the demonstration of a known plaintext, Brute- Force attack executing a linear search of the key space operating in exponential time O(2n) (where n is the bit-length of the key). Evaluation of this software leads to a debate on the implications of future cryptography and of computer security on a broader level. Keywords: Cryptanalysis, DES, RSA, Weiner Attack, Brute-Force
Table of Contents