Chris J. Mitchell

Bio: Chris J. Mitchell is an academic researcher from Royal Holloway, University of London. The author has contributed to research in topics: Authentication & Cryptography. The author has an hindex of 48, co-authored 397 publications receiving 10982 citations. Previous affiliations of Chris J. Mitchell include Johns Hopkins University & University of Portland.

Reputation methods for routing security for mobile ad hoc networks

Abstract: Mobile ad hoc networks have inherently very different properties to conventional networks. These new characteristics present major security vulnerabilities; in particular, one side effect of the unique way in which routing protocols operate in ad hoc networks is that many new threats arise. Selfish nodes are those which do not perform certain operations that the protocol specifies that they should, through a wish to conserve power. Malicious nodes may deliberately disrupt the network using a variety of attacks. The paper discusses reputation mechanisms which have been suggested as a means to mitigate the detrimental effect of selfish and malicious nodes. The paper reveals reasons why complex reputation systems may be too inefficient to use in a mobile ad hoc network, where resources are limited. However, suggestions are also made to show how a simple reputation system might be used to enhance the robustness of ad hoc networks.

User's guide to cryptography and standards

Abstract: With the scope and frequency of attacks on valuable corporate data growing enormously in recent years, a solid understanding of cryptography is essential for anyone working in the computer/network security field. This timely book delivers the hands-on knowledge you need, offering comprehensive coverage on the latest and most-important standardized cryptographic techniques to help you protect your data and computing resources to the fullest. Rather than focusing on theory like other books on the market, this unique resource describes cryptography from an end-user perspective, presenting in-depth, highly practical comparisons of standards and techniques. You learn, in detail, what cryptography can achieve and discover how to choose cryptographic standards that ensure state-of-the-art protection and maximum interoperability. Moreover, the book explains how to select standardized techniques that are most suitable for your specific needs. From encryption, cryptographic hash-functions, and message authentication codes, to digital signatures, authentication protocols, and public key infrastructures, this authoritative reference gives you complete working knowledge of the critical cryptographic tools being utilized world-wide. The book concludes with a look at the future of cryptography, including discussions on crypto-modules and biometrics.

Enumerating boolean functions of cryptographic significance

Abstract: In this paper we describe applications of functions from GF(2) m onto GF(2) n in the design of encryption algorithms. If such a function is to be useful it must satisfy a set of criteria, the actual definition of which depends on the type of encryption technique involved. This in turn means that it is important to ensure that the selected criteria do not restrict the choice of function too severely, i.e., the set of functions must be enumerated. We discuss some of the possible sets of criteria and then give partial results on the corresponding enumeration problems. Many open problems remain, some of them corresponding to well-known hard enumeration questions.

Impostor: a single sign-on system for use from untrusted devices

Abstract: At present, network users have to manage a set of authentication credentials (usually a username/password pair) for every service with which they are registered. Single sign-on (SSO) has been proposed as a solution to the usability, security and management implications of this situation. Under SSO, users need to manage only one set of authentication credentials in order to log into the services they subsequently use. This paper presents the design of an SSO system that is based on a trusted proxy, and that is suitable for use from an untrusted network access device. Unlike existing proxy-based SSO schemes, which require an infrastructure to be in place between the proxy and the service providers, the one presented here does not. An open-source implementation of the scheme, called 'Impostor', is also described. The prototype is implemented as an HTTP proxy, resulting in a system that works with common Web browsers.

Limitations of challenge-response entity authentication

Abstract: We consider two basic versions of the challenge-response authentication protocol, and exhibit both a method of attack and a simple modification preventing such attacks. We go on to consider three variants of the basic protocols and show that one of them is completely insecure.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Handbook of Applied Cryptography

Abstract: From the Publisher: A valuable reference for the novice as well as for the expert who needs a wider scope of coverage within the area of cryptography, this book provides easy and rapid access of information and includes more than 200 algorithms and protocols; more than 200 tables and figures; more than 1,000 numbered definitions, facts, examples, notes, and remarks; and over 1,250 significant references, including brief comments on each paper.

Tissue-based map of the human proteome

Abstract: Resolving the molecular details of proteome variation in the different tissues and organs of the human body will greatly increase our knowledge of human biology and disease. Here, we present a map of the human tissue proteome based on an integrated omics approach that involves quantitative transcriptomics at the tissue and organ level, combined with tissue microarray-based immunohistochemistry, to achieve spatial localization of proteins down to the single-cell level. Our tissue-based analysis detected more than 90% of the putative protein-coding genes. We used this approach to explore the human secretome, the membrane proteome, the druggable proteome, the cancer proteome, and the metabolic functions in 32 different tissues and organs. All the data are integrated in an interactive Web-based database that allows exploration of individual proteins, as well as navigation of global expression patterns, in all major tissues and organs in the human body.

Differential Power Analysis

Abstract: Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information.