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1	Security aspects of zero knowledge identification schemes Panait, Andreea Mihaela. January 2008 (has links) In this thesis we follow two directions: Zero Knowledge Protocols and the Discrete Logarithm Problem. In each direction we present the necessary background and we give a new approach for some parts of the existing protocols. / The new parts are dedicated to the soundness property of the Schnorr Identification Scheme and to the security of the sum+-Protocol. Since both directions are very well-known and studied in the field of cryptography, they are presented with many details so that the new results are easy to follow. / In writing this thesis we have tried to present the material in a specific order and in a manner easy to read even by beginners in cryptography. Zero-knowledge proofs. Cryptography -- Mathematics.
2	Security aspects of zero knowledge identification schemes Panait, Andreea Mihaela. January 2008 (has links) No description available. Cryptography -- Mathematics. Zero-knowledge proofs.
3	Classical and quantum strategies for bit commitment schemes in the two-prover model Simard, Jean-Raymond. January 2007 (has links) We show that the long-standing assumption of "no-communication" between the provers of the two-prover model is not sufficiently precise to guarantee the security of a bit commitment scheme against malicious adversaries. Indeed, we show how a simple correlated random variable, which does not allow to communicate, can be used to cheat a simplified version (sBGKW) of the bit commitment scheme of Ben-Or, Goldwasser, Kilian, and Wigderson [BGKW88]. Instead we propose a stronger notion of separation between the two provers which takes into account correlated computations. To emphasize the risk that entanglement still represents for the security of a commitment scheme despite the stronger notion of separation, we present two variations of the sBGKW scheme that can be cheated by quantum provers with probability (almost) one. A complete proof of security against quantum adversaries is then given for the sBGKW scheme. By reduction we also obtain the security of the original BGKW scheme against quantum provers. For the unfamiliar reader, basic notions of quantum processing are provided to facilitate the understanding of the proofs presented. Cryptography -- Mathematics. Zero-knowledge proofs. Quantum theory.
4	Classical and quantum strategies for bit commitment schemes in the two-prover model Simard, Jean-Raymond. January 2007 (has links) No description available. Cryptography -- Mathematics. Zero-knowledge proofs. Quantum theory.
5	Números primos e criptografia / Prime numbers and cryptography Spina, André Vinícius, 1986- 25 August 2018 (has links) Orientador: Ricardo Miranda Martins / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-25T03:12:47Z (GMT). No. of bitstreams: 1 Spina_AndreVinicius_M.pdf: 1532380 bytes, checksum: 1525ba4a0d466a2c148b8b1a485ccec2 (MD5) Previous issue date: 2014 / Resumo: A pesquisa apresentará uma introdução a Teoria dos Números através de uma abordagem sobre os métodos criptográficos RSA e Diffie-Hellman, onde pode-se constatar situações onde eles são eficientes. A teoria matemática presente nesse trabalho envolve conhecimentos em números primos, aritmética modular, testes de primalidade, grupos e outras questões envolvendo teoria dos números / Abstract: The paper presents a Number Theory introduction, trough a RSA and Diffie-Hellman cryptographic methods approach, where one can observe situations where they are effective. The mathematical theory introduced in this paper encompass prime numbers, Modular arithmetic,Primality test, groups and other Number Theory related branches / Mestrado / Matemática em Rede Nacional - PROFMAT / Mestre em Matemática em Rede Nacional - PROFMAT Números primos Criptografia - Matemática Primes numbers Cryptography - Mathematics
6	Tweakable Ciphers: Constructions and Applications Terashima, Robert Seth 07 August 2015 (has links) Tweakable ciphers are a building block used to construct a variety of cryptographic algorithms. Typically, one proves (via a reduction) that a tweakable-cipher-based algorithm is about as secure as the underlying tweakable cipher. Hence improving the security or performance of tweakable ciphers immediately provides corresponding benefits to the wide array of cryptographic algorithms that employ them. We introduce new tweakable ciphers, some of which have better security and others of which have better performance than previous designs. Moreover, we demonstrate that tweakable ciphers can be used directly (as opposed to as a building block) to provide authenticated encryption with associated data in a way that (1) is robust against common misuses and (2) can, in some cases, result in significantly shorter ciphertexts than other approaches. Cryptography -- Mathematics Computer security Computer systems -- Access control Data encryption (Computer science) Computer Sciences Theory and Algorithms
7	FPGA Implementations of Elliptic Curve Cryptography and Tate Pairing over Binary Field Huang, Jian 08 1900 (has links) Elliptic curve cryptography (ECC) is an alternative to traditional techniques for public key cryptography. It offers smaller key size without sacrificing security level. Tate pairing is a bilinear map used in identity based cryptography schemes. In a typical elliptic curve cryptosystem, elliptic curve point multiplication is the most computationally expensive component. Similarly, Tate pairing is also quite computationally expensive. Therefore, it is more attractive to implement the ECC and Tate pairing using hardware than using software. The bases of both ECC and Tate pairing are Galois field arithmetic units. In this thesis, I propose the FPGA implementations of the elliptic curve point multiplication in GF (2283) as well as Tate pairing computation on supersingular elliptic curve in GF (2283). I have designed and synthesized the elliptic curve point multiplication and Tate pairing module using Xilinx's FPGA, as well as synthesized all the Galois arithmetic units used in the designs. Experimental results demonstrate that the FPGA implementation can speedup the elliptic curve point multiplication by 31.6 times compared to software based implementation. The results also demonstrate that the FPGA implementation can speedup the Tate pairing computation by 152 times compared to software based implementation. FPGA elliptic curve cryptography Tate pairing Computer security. Data encryption (Computer science) Field programmable gate arrays. Curves, Elliptic. Cryptography -- Mathematics.
8	Smart card fault attacks on public key and elliptic curve cryptography Ling, Jie January 2014 (has links) Indiana University-Purdue University Indianapolis (IUPUI) / Blömmer, Otto, and Seifert presented a fault attack on elliptic curve scalar multiplication called the Sign Change Attack, which causes a fault that changes the sign of the accumulation point. As the use of a sign bit for an extended integer is highly unlikely, this appears to be a highly selective manipulation of the key stream. In this thesis we describe two plausible fault attacks on a smart card implementation of elliptic curve cryptography. King and Wang designed a new attack called counter fault attack by attacking the scalar multiple of discrete-log cryptosystem. They then successfully generalize this approach to a family of attacks. By implementing King and Wang's scheme on RSA, we successfully attacked RSA keys for a variety of sizes. Further, we generalized the attack model to an attack on any implementation that uses NAF and wNAF key. Smart Card RSA ECC Fault Attack Smart Card Security Public Key NAF wNAF Counter Fault Attack Bit Flip Attack Doubling Attack Attack Simulation Data encryption (Computer science) Curves, Elliptic -- Data processing Cryptography -- Mathematics Public key cryptography -- Research Data protection -- Research Computer engineering -- Research Coding theory Computer security Data structures (Computer science) Embedded computer systems Smart card industry Computer networks -- Security measures Computers -- Access control

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