Key management for wireless sensor network security

Wireless Sensor Networks (WSNs) have attracted great attention not only in industry but also in academia due to their enormous application potential and unique security challenges. A typical sensor network can be seen as a combination of a number of low-cost sensor nodes which have very limited computation and communication capability, memory space, and energy supply. The nodes are self-organized into a network to sense or monitor surrounding information in an unattended environment, while the self-organization property makes the networks vulnerable to various attacks.Many cryptographic mechanisms that solve network security problems rely directly on secure and efficient key management making key management a fundamental research topic in the field of WSNs security. Although key management for WSNs has been studied over the last years, the majority of the literature has focused on some assumed vulnerabilities along with corresponding countermeasures. Specific application, which is an important factor in determining the feasibility of the scheme, has been overlooked to a large extent in the existing literature.This thesis is an effort to develop a key management framework and specific schemes for WSNs by which different types of keys can be established and also can be distributed in a self-healing manner; explicit/ implicit authentication can be integrated according to the security requirements of expected applications. The proposed solutions would provide reliable and robust security infrastructure for facilitating secure communications in WSNs.There are five main parts in the thesis. In Part I, we begin with an introduction to the research background, problems definition and overview of existing solutions. From Part II to Part IV, we propose specific solutions, including purely Symmetric Key Cryptography based solutions, purely Public Key Cryptography based solutions, and a hybrid solution. While there is always a trade-off between security and performance, analysis and experimental results prove that each proposed solution can achieve the expected security aims with acceptable overheads for some specific applications. Finally, we recapitulate the main contribution of our work and identify future research directions in Part V

Quantum cryptography: key distribution and beyond

Uniquely among the sciences, quantum cryptography has driven both foundational research as well as practical real-life applications. We review the progress of quantum cryptography in the last decade, covering quantum key distribution and other applications.Comment: It's a review on quantum cryptography and it is not restricted to QK

Theory and Practice of Cryptography and Network Security Protocols and Technologies

In an age of explosive worldwide growth of electronic data storage and communications, effective protection of information has become a critical requirement. When used in coordination with other tools for ensuring information security, cryptography in all of its applications, including data confidentiality, data integrity, and user authentication, is a most powerful tool for protecting information. This book presents a collection of research work in the field of cryptography. It discusses some of the critical challenges that are being faced by the current computing world and also describes some mechanisms to defend against these challenges. It is a valuable source of knowledge for researchers, engineers, graduate and doctoral students working in the field of cryptography. It will also be useful for faculty members of graduate schools and universities

Computational Indistinguishability between Quantum States and Its Cryptographic Application

We introduce a computational problem of distinguishing between two specific quantum states as a new cryptographic problem to design a quantum cryptographic scheme that is "secure" against any polynomial-time quantum adversary. Our problem, QSCDff, is to distinguish between two types of random coset states with a hidden permutation over the symmetric group of finite degree. This naturally generalizes the commonly-used distinction problem between two probability distributions in computational cryptography. As our major contribution, we show that QSCDff has three properties of cryptographic interest: (i) QSCDff has a trapdoor; (ii) the average-case hardness of QSCDff coincides with its worst-case hardness; and (iii) QSCDff is computationally at least as hard as the graph automorphism problem in the worst case. These cryptographic properties enable us to construct a quantum public-key cryptosystem, which is likely to withstand any chosen plaintext attack of a polynomial-time quantum adversary. We further discuss a generalization of QSCDff, called QSCDcyc, and introduce a multi-bit encryption scheme that relies on similar cryptographic properties of QSCDcyc.Comment: 24 pages, 2 figures. We improved presentation, and added more detail proofs and follow-up of recent wor

Quantum Cryptography: Key Distribution and Beyond

Uniquely among the sciences, quantum cryptography has driven both foundational research as well as practical real-life applications. We review the progress of quantum cryptography in the last decade, covering quantum key distribution and other applications.Quanta 2017; 6: 1–47

Quantum-based security in optical fibre networks

Electronic communication is used everyday for a number of different applications. Some of the information transferred during these communications can be private requiring encryption and authentication protocols to keep this information secure. Although there are protocols today which provide some security, they are not necessarily unconditionally secure. Quantum based protocols on the other hand, can provide unconditionally secure protocols for encryption and authentication. Prior to this Thesis, only one experimental realisation of quantum digital signatures had been demonstrated. This used a lossy photonic device along with a quantum memory allowing two parties to test whether they were sent the same signature by a single sender, and also store the quantum states for measurement later. This restricted the demonstration to distances of only a few metres, and was tested with a primitive approximation of a quantum memory rather than an actual one. This Thesis presents an experimental realisation of a quantum digital signature protocol which removes the reliance on quantum memory at the receivers, making a major step towards practicality. By removing the quantum memory, it was also possible to perform the swap and comparison mechanism in a more efficient manner resulting in an experimental realisation of quantum digital signatures over 2 kilometres of optical fibre. Quantum communication protocols can be unconditionally secure, however the transmission distance is limited by loss in quantum channels. To overcome this loss in conventional channels an optical amplifier is used, however the added noise from these would swamp the quantum signal if directly used in quantum communications. This Thesis looked into probabilistic quantum amplification, with an experimental realisation of the state comparison amplifier, based on linear optical components and single-photon detectors. The state comparison amplifier operated by using the wellestablished techniques of optical coherent state comparison and weak subtraction to post-select the output and provide non-deterministic amplification with increased fidelity at a high repetition rate. The success rates of this amplifier were found to be orders of magnitude greater than other state of the art quantum amplifiers, due to its lack of requirement for complex quantum resources, such as single or entangled photon sources, and photon number resolving detectors