Award Date


Degree Type


Degree Name

Master of Science (MS)


Computer Science

First Committee Member

Yoohwan Kim

Number of Pages



Cryptographers need to provide the world with a new encryption standard. DES, the major encryption algorithm for the past fifteen years, is nearing the end of its useful life. Its 56-bit key size is vulnerable to a brute-force attack on powerful microprocessors and recent advances in linear cryptanalysis and differential cryptanalysis indicate that DES is vulnerable to other attacks as well. A more recent attack called XSL, proposes a new attack against AES and Serpent. The attack depends much more critically on the complexity of the nonlinear components than on the number of rounds. Ciphers with small S-boxes and simple structures are particularly vulnerable. Serpent has small S-boxes and a simple structure. AES has larger S-boxes, but a very simple algebraic description. If the attack is proven to be correct, cryptographers predict it to break AES with a 2; 80 complexity, over the coming years; Many of the other unbroken algorithms---Khufu, REDOC II, and IDEA---are protected by patents. RC2 is broken. The U.S. government has declassified the Skipjack algorithm in the Clipper and Capstone chips.


Algorithm; Analysis; Applications; Cryptography; Design; Dynamic; Implementation

Controlled Subject

Computer science

File Format


File Size

2211.84 KB

Degree Grantor

University of Nevada, Las Vegas




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