122 research outputs found
The Quantum Frontier
The success of the abstract model of computation, in terms of bits, logical
operations, programming language constructs, and the like, makes it easy to
forget that computation is a physical process. Our cherished notions of
computation and information are grounded in classical mechanics, but the
physics underlying our world is quantum. In the early 80s researchers began to
ask how computation would change if we adopted a quantum mechanical, instead of
a classical mechanical, view of computation. Slowly, a new picture of
computation arose, one that gave rise to a variety of faster algorithms, novel
cryptographic mechanisms, and alternative methods of communication. Small
quantum information processing devices have been built, and efforts are
underway to build larger ones. Even apart from the existence of these devices,
the quantum view on information processing has provided significant insight
into the nature of computation and information, and a deeper understanding of
the physics of our universe and its connections with computation.
We start by describing aspects of quantum mechanics that are at the heart of
a quantum view of information processing. We give our own idiosyncratic view of
a number of these topics in the hopes of correcting common misconceptions and
highlighting aspects that are often overlooked. A number of the phenomena
described were initially viewed as oddities of quantum mechanics. It was
quantum information processing, first quantum cryptography and then, more
dramatically, quantum computing, that turned the tables and showed that these
oddities could be put to practical effect. It is these application we describe
next. We conclude with a section describing some of the many questions left for
future work, especially the mysteries surrounding where the power of quantum
information ultimately comes from.Comment: Invited book chapter for Computation for Humanity - Information
Technology to Advance Society to be published by CRC Press. Concepts
clarified and style made more uniform in version 2. Many thanks to the
referees for their suggestions for improvement
Secure Hardware Implementation of Post Quantum Cryptosystems
Solving a hard mathematical problem is the security basis of all current cryptographic systems. With the realization of a large scale quantum computer, hard mathematical problems such as integer factorization and discrete logarithmic problems will be easily solved with special algorithms implemented on such a computer. Indeed, only post-quantum cryptosystems which defy quantum attacks will survive in the post-quantum era. Each newly proposed post-quantum cryptosystem has to be scrutinized against all different types of attacks. Attacks can be classified into mathematical cryptanalysis and side channel attacks. In this thesis, we propose secure hardware implementations against side channel attacks for two of the most promising post-quantum algorithms: the lattice-based public key cryptosystem, NTRU, and the multivariate public key cryptosystem, Rainbow, against power analysis attacks and fault analysis attacks, respectively.
NTRUEncrypt is a family of public key cryptosystems that uses lattice-based cryptography. It has been accepted as an IEEE P1363 standard and as an X9.98 Standard. In addition to its small footprint compared to other number theory based public key systems, its resistance to quantum attacks makes it a very attractive candidate for post quantum cryptosystems. On the other hand, similar to other cryptographic schemes, unprotected hardware implementations of NTRUEncrypt are susceptible to side channel attacks such as timing and power analysis. In this thesis, we present an FPGA implementation of NTRUEncrypt which is resistant to first order differential power analysis (DPA) attacks. Our countermeasures are implemented at the architecture level. In particular, we split the ciphertext into two randomly generated shares. This guarantees that during the first step of the decryption process, the inputs to the convolution modules, which are convoluted with the secret key polynomial, are uniformly chosen random polynomials which are freshly generated for each convolution operation and are not under the control of the attacker. The two shares are then processed in parallel without explicitly combining them until the final stage of the decryption. Furthermore, during the final stage of the decryption, we also split the used secret key polynomial into two randomly generated shares which provides theoretical resistance against the considered class of power analysis attacks. The proposed architecture is implemented using Altera Cyclone IV FPGA and simulated on Quartus II in order to compare the non-masked architecture with the masked one. For the considered set of parameters, the area overhead of the protected implementation is about 60% while the latency overhead is between 1.4% to 6.9%.
Multivariate Public Key Cryptosystems (MPKCs) are cryptographic schemes based on the difficulty of solving a set of multivariate system of nonlinear equations over a finite field. MPKCs are considered to be secure against quantum attacks. Rainbow, an MPKC signature scheme, is among the leading MPKC candidates for post quantum cryptography. In this thesis, we propose and compare two fault analysis-resistant implementations for the Rainbow signature scheme. The hardware platform for our implementations is Xilinx FPGA Virtex 7 family. Our implementation for the Rainbow signature completes in 191 cycles using a 20ns clock period which is an improvement over the previously reported implementations. The verification completes in 141 cycles using the same clock period. The two proposed fault analysis-resistant schemes offer different levels of protections and increase the area overhead by a factor of 33% and 9%, respectively. The first protection scheme acquires a time overhead of about 72%, but the second one does not have any time overhead
Post-Quantum Ciphers
Národný inštitút pre štandardy a technológie (NIST) zahájil proces na získanie, vyhodnotenie a štandardizáciu jedného alebo viacerých kryptografických algoritmov využívajúcich verejný kľúč prostredníctvom verejnej súťaže. Cieľom tejto dimplomovej práce je naštudovať dostupné postkvantové algoritmy pre ustanovenie kľúča, ktoré boli zverejnené v treťom kole tejto súťaže. Po dôkladnej analýze a porovnaní bol jeden zo študovaných algoritmov implementovaný s využitím knižníc dostupných pre daný algoritmus, následne bol program optimalizovaný a zdokumentovaný.The National Institute for Standards and Technology (NIST) has initiated a process to solicit, evaluate, and standardize one or more quantum-resistant public-key cryptography algorithms through a public competition. An objective of this thesis is to study the available post-quantum algorithms for key establishment, that were published in the third round of this competition. After a proper analysis and comparison, one of the studied algorithms was implemented using available libraries for the chosen algorithm, the created program was optimized and documented.
Semi-Quantum Conference Key Agreement (SQCKA)
A need in the development of secure quantum communications is the scalable extension
of key distribution protocols. The greatest advantage of these protocols is the fact that its
security does not rely on mathematical assumptions and can achieve perfect secrecy. In
order to make these protocols scalable, has been developed the concept of Conference
Key Agreements, among multiple users.
In this thesis we propose a key distribution protocol among several users using a
semi-quantum approach. We assume that only one of the users is equipped with quantum
devices and generates quantum states, while the other users are classical, i.e., they are only
equipped with a device capable of measuring or reflecting the information. This approach has
the advantage of simplicity and reduced costs.
We prove our proposal is secure and we present some numerical results on the lower
bounds for the key rate. The security proof applies new techniques derived from some
already well established work.
From the practical point of view, we developed a toolkit called Qis|krypt⟩ that is able to
simulate not only our protocol but also some well-known quantum key distribution protocols.
The source-code is available on the following link:
- https://github.com/qiskrypt/qiskrypt/.Uma das necessidades no desenvolvimento de comunicações quânticas seguras é a extensão
escalável de protocolos de distribuição de chaves. A grande vantagem destes protocolos é o
facto da sua segurança não depender de suposições matemáticas e poder atingir segurança
perfeita. Para tornar estes protocolos escaláveis, desenvolveu-se o conceito de Acordo
de Chaves de Conferência, entre múltiplos utilizadores.
Nesta tese propomos um protocolo para distribuição de chaves entre vários utilizadores
usando uma abordagem semi-quântica. Assumimos que apenas um dos utilizadores está
equipado com dispositivos quânticos e é capaz de gerar estados quânticos, enquanto que
os outros utilizadores são clássicos, isto é, estão apenas equipados com dispositivos capazes
de efectuar uma medição ou refletir a informação. Esta abordagem tem a vantagem de ser
mais simples e de reduzir custos.
Provamos que a nossa proposta é segura e apresentamos alguns resultados numéricos
sobre limites inferiores para o rácio de geração de chaves. A prova de segurança aplica novas
técnicas derivadas de alguns resultados já bem estabelecidos.
Do ponto de vista prático, desenvolvemos uma ferramenta chamada Qis|krypt⟩ que é capaz
de simular não só o nosso protocolo como também outros protocolos distribuição de chaves
bem conhecidos. O código fonte encontra-se disponível no seguinte link:
- https://github.com/qiskrypt/qiskrypt/
International Symposium on Mathematics, Quantum Theory, and Cryptography
This open access book presents selected papers from International Symposium on Mathematics, Quantum Theory, and Cryptography (MQC), which was held on September 25-27, 2019 in Fukuoka, Japan. The international symposium MQC addresses the mathematics and quantum theory underlying secure modeling of the post quantum cryptography including e.g. mathematical study of the light-matter interaction models as well as quantum computing. The security of the most widely used RSA cryptosystem is based on the difficulty of factoring large integers. However, in 1994 Shor proposed a quantum polynomial time algorithm for factoring integers, and the RSA cryptosystem is no longer secure in the quantum computing model. This vulnerability has prompted research into post-quantum cryptography using alternative mathematical problems that are secure in the era of quantum computers. In this regard, the National Institute of Standards and Technology (NIST) began to standardize post-quantum cryptography in 2016. This book is suitable for postgraduate students in mathematics and computer science, as well as for experts in industry working on post-quantum cryptography
International Symposium on Mathematics, Quantum Theory, and Cryptography
This open access book presents selected papers from International Symposium on Mathematics, Quantum Theory, and Cryptography (MQC), which was held on September 25-27, 2019 in Fukuoka, Japan. The international symposium MQC addresses the mathematics and quantum theory underlying secure modeling of the post quantum cryptography including e.g. mathematical study of the light-matter interaction models as well as quantum computing. The security of the most widely used RSA cryptosystem is based on the difficulty of factoring large integers. However, in 1994 Shor proposed a quantum polynomial time algorithm for factoring integers, and the RSA cryptosystem is no longer secure in the quantum computing model. This vulnerability has prompted research into post-quantum cryptography using alternative mathematical problems that are secure in the era of quantum computers. In this regard, the National Institute of Standards and Technology (NIST) began to standardize post-quantum cryptography in 2016. This book is suitable for postgraduate students in mathematics and computer science, as well as for experts in industry working on post-quantum cryptography
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