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 Title
 An algebraic attack on block ciphers.
 Creator
 Matheis, Kenneth., Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

The aim of this work is to investigate an algebraic attack on block ciphers called Multiple Right Hand Sides (MRHS). MRHS models a block cipher as a system of n matrix equations Si := Aix = [Li], where each Li can be expressed as a set of its columns bi1, . . . , bisi . The set of solutions Ti of Si is dened as the union of the solutions of Aix = bij , and the set of solutions of the system S1, . . . , Sn is dened as the intersection of T1, . . . , Tn. Our main contribution is a hardware...
Show moreThe aim of this work is to investigate an algebraic attack on block ciphers called Multiple Right Hand Sides (MRHS). MRHS models a block cipher as a system of n matrix equations Si := Aix = [Li], where each Li can be expressed as a set of its columns bi1, . . . , bisi . The set of solutions Ti of Si is dened as the union of the solutions of Aix = bij , and the set of solutions of the system S1, . . . , Sn is dened as the intersection of T1, . . . , Tn. Our main contribution is a hardware platform which implements a particular algorithm that solves MRHS systems (and hence block ciphers). The case is made that the platform performs several thousand orders of magnitude faster than software, it costs less than US$1,000,000, and that actual times of block cipher breakage can be calculated once it is known how the corresponding software behaves. Options in MRHS are also explored with a view to increase its efficiency.
Show less  Date Issued
 2010
 PURL
 http://purl.flvc.org/FAU/2976444
 Subject Headings
 Ciphers, Cryptography, Data encryption (Computer science), Computer security, Coding theory, Integrated circuits, Design and construction
 Format
 Document (PDF)
 Title
 Quantum Circuits for Cryptanalysis.
 Creator
 Amento, Brittanney Jaclyn, Steinwandt, Rainer, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

Finite elds of the form F2m play an important role in coding theory and cryptography. We show that the choice of how to represent the elements of these elds can have a signi cant impact on the resource requirements for quantum arithmetic. In particular, we show how the Gaussian normal basis representations and \ghostbit basis" representations can be used to implement inverters with a quantum circuit of depth O(mlog(m)). To the best of our knowledge, this is the rst construction with...
Show moreFinite elds of the form F2m play an important role in coding theory and cryptography. We show that the choice of how to represent the elements of these elds can have a signi cant impact on the resource requirements for quantum arithmetic. In particular, we show how the Gaussian normal basis representations and \ghostbit basis" representations can be used to implement inverters with a quantum circuit of depth O(mlog(m)). To the best of our knowledge, this is the rst construction with subquadratic depth reported in the literature. Our quantum circuit for the computation of multiplicative inverses is based on the ItohTsujii algorithm which exploits the property that, in a normal basis representation, squaring corresponds to a permutation of the coe cients. We give resource estimates for the resulting quantum circuit for inversion over binary elds F2m based on an elementary gate set that is useful for faulttolerant implementation. Elliptic curves over nite elds F2m play a prominent role in modern cryptography. Published quantum algorithms dealing with such curves build on a short Weierstrass form in combination with a ne or projective coordinates. In this thesis we show that changing the curve representation allows a substantial reduction in the number of Tgates needed to implement the curve arithmetic. As a tool, we present a quantum circuit for computing multiplicative inverses in F2m in depth O(mlogm) using a polynomial basis representation, which may be of independent interest. Finally, we change our focus from the design of circuits which aim at attacking computational assumptions on asymmetric cryptographic algorithms to the design of a circuit attacking a symmetric cryptographic algorithm. We consider a block cipher, SERPENT, and our design of a quantum circuit implementing this cipher to be used for a key attack using Grover's algorithm as in [18]. This quantum circuit is essential for understanding the complexity of Grover's algorithm.
Show less  Date Issued
 2016
 PURL
 http://purl.flvc.org/fau/fd/FA00004662, http://purl.flvc.org/fau/fd/FA00004662
 Subject Headings
 Artificial intelligence, Computer networks, Cryptography, Data encryption (Computer science), Finite fields (Algebra), Quantum theory
 Format
 Document (PDF)
 Title
 Permutationbased transformations for digital multimedia encryption and steganography.
 Creator
 Socek, Daniel, Florida Atlantic University, Furht, Borko, Magliveras, Spyros S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

The aim of this work is to explore the utilization of permutationbased transformations to achieve compression, encryption and steganography in the domain of digital videos. The main contribution of this dissertation is a novel type of digital video encryption that has several advantages over other currently available digital video encryption methods. An extended classification of digital video encryption algorithms is presented in order to clarify these advantages. The classification itself...
Show moreThe aim of this work is to explore the utilization of permutationbased transformations to achieve compression, encryption and steganography in the domain of digital videos. The main contribution of this dissertation is a novel type of digital video encryption that has several advantages over other currently available digital video encryption methods. An extended classification of digital video encryption algorithms is presented in order to clarify these advantages. The classification itself represents an original work, since to date, no such comprehensive classification is provided in known scientific literature. Both security and performance aspects of the proposed method are thoroughly analyzed to provide evidence for high security and performance efficiency. Since the basic model is feasible only for a certain class of video sequences and video codecs, several extensions providing broader applicability are described along with the basic algorithm. An additional significant contribution is the proposition of a novel type of digital video steganography based on disguising a given video by another video. Experimental results are generated for a number of video sequences to demonstrate the performance of proposed methods.
Show less  Date Issued
 2006
 PURL
 http://purl.flvc.org/fcla/dt/12225
 Subject Headings
 Image processingSecurity measures, Data encryption (Computer science), Computer security, Multimedia systemsSecurity measures
 Format
 Document (PDF)
 Title
 Message authentication in an identitybased encryption scheme: 1KeyEncryptThenMAC.
 Creator
 Amento, Brittanney Jaclyn, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

We present an IdentityBased Encryption scheme, 1KeyEncryptThenMAC, in which we are able to verify the authenticity of messages using a MAC. We accomplish this authentication by combining an IdentityBased Encryption scheme given by Boneh and Franklin, with an IdentityBased NonInteractive Key Distribution given by Paterson and Srinivasan, and attaching a MAC. We prove the scheme is chosen plaintext secure and chosen ciphertext secure, and the MAC is existentially unforgeable.
 Date Issued
 2010
 PURL
 http://purl.flvc.org/FAU/2796050
 Subject Headings
 Data encryption (Computer science), Public key cryptopgraphy, Public key infrastructure (Computer security)
 Format
 Document (PDF)
 Title
 Universal physical access control system (UPACS).
 Creator
 Carryl, Clyde, Alhalabi, Bassem A., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

This research addresses the need for increased interoperability between the varied access control systems in use today, and for a secure means of providing access to remote physical devices over untrusted networks. The Universal Physical Access Control System (UPACS) is an encryptionenabled security protocol that provides a standard customizable device control mechanism that can be used to control the behavior of a wide variety of physical devices, and provide users the ability to securely...
Show moreThis research addresses the need for increased interoperability between the varied access control systems in use today, and for a secure means of providing access to remote physical devices over untrusted networks. The Universal Physical Access Control System (UPACS) is an encryptionenabled security protocol that provides a standard customizable device control mechanism that can be used to control the behavior of a wide variety of physical devices, and provide users the ability to securely access those physical devices over untrusted networks.
Show less  Date Issued
 2015
 PURL
 http://purl.flvc.org/fau/fd/FA00004354, http://purl.flvc.org/fau/fd/FA00004354
 Subject Headings
 Body area networks (Electronics), Computational complexity, Computer network protocols, Computer security, Cryptography, Data encryption (Computer science), Data structures (Computer science), Telecommunication  Security measures
 Format
 Document (PDF)
 Title
 An innovative pixel scoring method for watermarking of binary document images.
 Creator
 Furht, Borko, Muharemagic, Edin
 Date Issued
 20080709  20060712
 PURL
 http://purl.flvc.org/fcla/dt/363492
 Subject Headings
 Digital watermarking., Multimedia systems Security measures., Data encryption (Computer science) Technological innovations.
 Format
 Document (PDF)
 Title
 New approaches to encryption and steganography for digital videos.
 Creator
 Furht, Borko, Socek, Daniel, Kalva, Hari, Magliveras, Spyros S., Marques, Oge, Culibrk, Dubravko
 Date Issued
 2007
 PURL
 http://purl.flvc.org/fcla/dt/337435
 Subject Headings
 Multimedia systems Security measures., Digital video., Digital watermarking., Data encryption (Computer science) Technological innovations., Cryptography.
 Format
 Document (PDF)
 Title
 Signature schemes in single and multiuser settings.
 Creator
 Villanyi, Viktoria., Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

In the first chapters we will give a short introduction to signature schemes in single and multiuser settings. We give the definition of a signature scheme and explain a group of possible attacks on them. In Chapter 6 we give a construction which derives a subliminalfree RSA public key. In the construction we use a computationally binding and unconditionally hiding commitment scheme. To establish a subliminalfree RSA modulus n, we have to construct the secret primes p and q. To prove p and...
Show moreIn the first chapters we will give a short introduction to signature schemes in single and multiuser settings. We give the definition of a signature scheme and explain a group of possible attacks on them. In Chapter 6 we give a construction which derives a subliminalfree RSA public key. In the construction we use a computationally binding and unconditionally hiding commitment scheme. To establish a subliminalfree RSA modulus n, we have to construct the secret primes p and q. To prove p and q are primes we use Lehmann's primality test on the commitments. The chapter is based on the paper, "RSA signature schemes with subliminalfree public key" (Tatra Mountains Mathematical Publications 41 (2008)). In chapter 7 a onetime signature scheme using runlength encoding is presented, which in the random oracle model offers security against chosenmessage attacks. For parameters of interest, the proposed scheme enables about 33% faster verification with a comparable signature size than a construction of Merkle and Winternitz. The public key size remains unchanged (1 hash value). The main cost for the faster verification is an increase in the time required for signing messages and for key generation. The chapter is based on the paper "A onetime signature using runlength encoding" (Information Processing Letters Vol. 108, Issue 4, (2008)).
Show less  Date Issued
 2009
 PURL
 http://purl.flvc.org/FAU/215289
 Subject Headings
 Information technology, Security measures, Cryptography, Coding theory, Data encryption (Computer science), DIgital watermarking
 Format
 Document (PDF)
 Title
 Signature system for video identification.
 Creator
 Medellin, Sebastian Possos., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

Video signature techniques based on tomography images address the problem of video identification. This method relies on temporal segmentation and sampling strategies to build and determine the unique elements that will form the signature. In this thesis an extension for these methods is presented; first a new feature extraction method, derived from the previously proposed sampling pattern, is implemented and tested, resulting in a highly distinctive set of signature elements, second a robust...
Show moreVideo signature techniques based on tomography images address the problem of video identification. This method relies on temporal segmentation and sampling strategies to build and determine the unique elements that will form the signature. In this thesis an extension for these methods is presented; first a new feature extraction method, derived from the previously proposed sampling pattern, is implemented and tested, resulting in a highly distinctive set of signature elements, second a robust temporal video segmentation system is used to replace the original method applied to determine shot changes more accurately. Under a very exhaustive set of tests the system was able to achieve 99.58% of recall, 100% of precision and 99.35% of prediction precision.
Show less  Date Issued
 2010
 PURL
 http://purl.flvc.org/FAU/2683534
 Subject Headings
 Biometric identification, Image processing, Digital techniques, Pattern recognition systems, Data encryption (Computer science)
 Format
 Document (PDF)
 Title
 New Results in Group Theoretic Cryptology.
 Creator
 Sramka, Michal, Florida Atlantic University, Magliveras, Spyros S., Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

With the publication of Shor's quantum algorithm for solving discrete logarithms in finite cyclic groups, a need for new cryptographic primitives arose; namely, for more secure primitives that would prevail in the postquantum era. The aim of this dissertation is to exploit some hard problems arising from group theory for use in cryptography. Over the years, there have been many such proposals. We first look at two recently proposed schemes based on some form of a generalization of the...
Show moreWith the publication of Shor's quantum algorithm for solving discrete logarithms in finite cyclic groups, a need for new cryptographic primitives arose; namely, for more secure primitives that would prevail in the postquantum era. The aim of this dissertation is to exploit some hard problems arising from group theory for use in cryptography. Over the years, there have been many such proposals. We first look at two recently proposed schemes based on some form of a generalization of the discrete logari thm problem (DLP), identify their weaknesses, and cryptanalyze them. By applying the exper tise gained from the above cryptanalyses, we define our own generalization of the DLP to arbitrary finite groups. We show that such a definition leads to the design of signature schemes and pseudorandom number generators with provable security under a security assumption based on a group theoretic problem. In particular, our security assumption is based on the hardness of factorizing elements of the projective special linear group over a finite field in some representations. We construct a oneway function based on this group theoretic assumption and provide a security proof.
Show less  Date Issued
 2006
 PURL
 http://purl.flvc.org/fau/fd/FA00000878
 Subject Headings
 Group theory, Mathematical statistics, Cryptography, Combinatorial designs and configurations, Data encryption (Computer science), Coding theory
 Format
 Document (PDF)
 Title
 Web services cryptographic patterns.
 Creator
 Hashizume, Keiko., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

Data security has been identified as one of the most important concerns where sensitive messages are exchanged over the network. In web service architecture, multiple distributed applications communicate with each other over the network by sending XML messages. How can we protect these sensitive messages? Some web services standards have emerged to tackle this problem. The XML Encryption standard defines the process of encrypting and decrypting all of an XML message, part of an XML message,...
Show moreData security has been identified as one of the most important concerns where sensitive messages are exchanged over the network. In web service architecture, multiple distributed applications communicate with each other over the network by sending XML messages. How can we protect these sensitive messages? Some web services standards have emerged to tackle this problem. The XML Encryption standard defines the process of encrypting and decrypting all of an XML message, part of an XML message, or even an external resource. Like XML Encryption, the XML Signature standard specifies how to digitally sign an entire XML message, part of an XML message, or an external object. WSSecurity defines how to embed security tokens, XML encryption, and XML signature into XML documents. It does not define new security mechanisms, but leverages existing security technologies such as encryption and digital signature.
Show less  Date Issued
 2009
 PURL
 http://purl.flvc.org/FAU/216413
 Subject Headings
 Computer networks, Access control, Data encryption (Computer science), XML (Document markup language), Digital signatures, Computer network architectures
 Format
 Document (PDF)
 Title
 Physical Layer Security of Wireless Transmissions Over Fading Channels.
 Creator
 Blanc, Sadrac, Aalo, Valentine A., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

The open nature of the wireless medium makes the wireless communication susceptible to eavesdropping attacks. In addition, fading and shadowing significantly degrade the performance of the communication system in the wireless networks. A versatile approach to circumvent the issues of eavesdropping attacks while exploiting the physical properties of the wireless channel is the socalled physical layersecurity. In this work, we consider a model in which two legitimate users communicate in the...
Show moreThe open nature of the wireless medium makes the wireless communication susceptible to eavesdropping attacks. In addition, fading and shadowing significantly degrade the performance of the communication system in the wireless networks. A versatile approach to circumvent the issues of eavesdropping attacks while exploiting the physical properties of the wireless channel is the socalled physical layersecurity. In this work, we consider a model in which two legitimate users communicate in the presence of an eavesdropper. We investigate the performance of the wireless network at the physical layer that is subject to a variety of fading environments that may be modeled by the Rayleigh, Nakagamim, and GeneralizedK distributions, to mention a few. We use the secrecy outage probability (SOP) as the standard performance metrics to study the performance of the wireless networks. We propose two different approaches to compute the secrecy outage probability, and derive explicit expressions for the secrecy outage probability that allow us to characterize the performance of the wireless networks. Specifically, we use a direct integration approach as well as a Taylor series base approach to evaluate the secrecy outage probability. Finally, we use computer simulations, based on MATLAB, to confirm the analytical results.
Show less  Date Issued
 2016
 PURL
 http://purl.flvc.org/fau/fd/FA00004729, http://purl.flvc.org/fau/fd/FA00004729
 Subject Headings
 Data encryption (Computer science), Digital communications  Reliability  Mathematics, Internetworking (Telecommunication), Radio wave propagation, Wireless communication systems  Security measures
 Format
 Document (PDF)
 Title
 Low rank transitive representations, primitive extensions, and the collision problem in PSL (2, q).
 Creator
 Thapa Magar, Krishna B., Magliveras, Spyros S., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

Every transitive permutation representation of a finite group is the representation of the group in its action on the cosets of a particular subgroup of the group. The group has a certain rank for each of these representations. We first find almost all rank3 and rank4 transitive representations of the projective special linear group P SL(2, q) where q = pm and p is an odd prime. We also determine the rank of P SL (2, p) in terms of p on the cosets of particular given subgroups. We then...
Show moreEvery transitive permutation representation of a finite group is the representation of the group in its action on the cosets of a particular subgroup of the group. The group has a certain rank for each of these representations. We first find almost all rank3 and rank4 transitive representations of the projective special linear group P SL(2, q) where q = pm and p is an odd prime. We also determine the rank of P SL (2, p) in terms of p on the cosets of particular given subgroups. We then investigate the construction of rank3 transitive and primitive extensions of a simple group, such that the extension group formed is also simple. In the latter context we present a new, group theoretic construction of the famous HoffmanSingleton graph as a rank3 graph.
Show less  Date Issued
 2015
 PURL
 http://purl.flvc.org/fau/fd/FA00004471, http://purl.flvc.org/fau/fd/FA00004471
 Subject Headings
 Combinatorial designs and configurations, Cryptography, Data encryption (Computer science), Finite geometries, Finite groups, Group theory, Permutation groups
 Format
 Document (PDF)
 Title
 Efficient implementation of zeroknowledge based identification protocols.
 Creator
 Barella, Michelle Elizabeth., Florida Atlantic University, Mullin, Ronald C.
 Abstract/Description

A zero knowledge identification protocol is an interactive proof system that allows a person to prove that he knows a secret key associated with his identity without revealing the secret key. This type of protocol is the topic of a fairy tale, by Gustavus Simmons called the King's Dilemma, about a king and the problem he has with thieves impersonating his tax collectors. It describes a zeroknowledge identification protocol that will rid the king of his problem. I present this system, the...
Show moreA zero knowledge identification protocol is an interactive proof system that allows a person to prove that he knows a secret key associated with his identity without revealing the secret key. This type of protocol is the topic of a fairy tale, by Gustavus Simmons called the King's Dilemma, about a king and the problem he has with thieves impersonating his tax collectors. It describes a zeroknowledge identification protocol that will rid the king of his problem. I present this system, the motivation for this thesis, and the transformations from this protocol, that uses lead weights and containers, to protocols that use mathematical elements. The security of these protocols is determined by the complexity of the underlying mathematical problem, such as the knapsack and discrete logarithm problem, and three properties: completeness, soundness, and zero knowledge.
Show less  Date Issued
 2004
 PURL
 http://purl.flvc.org/fcla/dt/13181
 Subject Headings
 Cryptography, Telecommunication systemsSecurity measures, Knapsack problem (Mathematics), Mathematical optimization, Finite fields (Algebra), Data encryption (Computer science)
 Format
 Document (PDF)
 Title
 Distinguishability of Public Keys and Experimental Validation: The McEliece PublicKeyed Cryptosystem.
 Creator
 Pham, Hai, Steinwandt, Rainer, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

As quantum computers continue to develop, they pose a threat to cryptography since many popular cryptosystems will be rendered vulnerable. This is because the security of most currently used asymmetric systems requires the computational hardness of the integer factorization problem, the discrete logarithm or the elliptic curve discrete logarithm problem. However, there are still some cryptosystems that resist quantum computing. We will look at codebased cryptography in general and the...
Show moreAs quantum computers continue to develop, they pose a threat to cryptography since many popular cryptosystems will be rendered vulnerable. This is because the security of most currently used asymmetric systems requires the computational hardness of the integer factorization problem, the discrete logarithm or the elliptic curve discrete logarithm problem. However, there are still some cryptosystems that resist quantum computing. We will look at codebased cryptography in general and the McEliece cryptosystem specifically. Our goal is to understand the structure behind the McEliece scheme, including the encryption and decryption processes, and what some advantages and disadvantages are that the system has to offer. In addition, using the results from Courtois, Finiasz, and Sendrier's paper in 2001, we will discuss a digital signature scheme based on the McEliece cryptosystem. We analyze one classical algebraic attack against the security analysis of the system based on the distinguishing problem whether the public key of the McEliece scheme is generated from a generating matrix of a binary Goppa code or a random binary matrix. The idea of the attack involves solving an algebraic system of equations and we examine the dimension of the solution space of the linearized system of equations. With the assistance from a paper in 2010 by Faugere, GauthierUmana, Otmani, Perret, Tillich, we will see the parameters needed for the intractability of the distinguishing problem.
Show less  Date Issued
 2015
 PURL
 http://purl.flvc.org/fau/fd/FA00004535, http://purl.flvc.org/fau/fd/FA00004535
 Subject Headings
 Coding theory, Combinatorial analysis, Data encryption (Computer science), Data transmission systems  Security measures, Information theory, McEliece, Robert J.  Influence, Public key cryptography
 Format
 Document (PDF)