Contents Acknowledgements vii Abstract viii 1 Introduction 1 1.
Bibliography 85 ii Acknowledgments My foremost thanks go to my advisor Jack Lutz. Jack brought me into research in 1999 while I was still an undergraduate. In the four years since he has provided me with excellent research advice and I have thoroughly enjoyed working with him. thank them for collaborating with me. I also thank Pavan Aduri, Cliff Bergman,… (More)
Two algebraic structures A and B are called categorically equivalent if there is a functor from the variety generated by A to the variety generated by B, carrying A to B, that is an equivalence of the varieties when viewed as categories. We characterize those algebras categorically equivalent to A when A is an algebra whose set of term operations is as… (More)
This paper introduces the Adopted-Pet (AP) protocol, an automatic (i.e. requiring no human interaction) secure pairing protocol, adequate for the pairing between a passive RFID tag and a reader. Most pairing protocols rely for their security on a certain advantage that the legitimate devices have over any malicious users. Such advantages include proximity… (More)
In this paper we consider the complexity of several problems involving finite algebraic structures. Given finite algebras A and B, these problems ask the following. (1) Do A and B satisfy precisely the same identities? (2) Do they satisfy the same quasi-identities? (3) Do A and B have the same set of term operations? In addition to the general case in which… (More)
Steganography is the study of data hiding for the purpose of covert communication. A secret message is inserted into a cover file so that the very existence of the message is not apparent. Most current steganography algorithms insert data in the spatial or transform domains; common transforms include the discrete cosine transform, the discrete Fourier… (More)
Two algebraic structures with the same universe are called term-equivalent if they have the same clone of term operations. We show that the problem of determining whether two finite algebras of finite similarity type are term-equivalent is complete for deterministic exponential time. When are two algebraic structures (presumably of different similarity… (More)
Hiding messages in image data, called steganography, is used by criminals and noncriminals alike to send information over the internet. The detection of hidden messages in image data stored on websites and computers, called steganalysis, is of prime importance to cyber forensics. Automated detection of hidden messages is a requirement, since the shear… (More)