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.

Handbook of Applied Cryptography

Distributed Sensor Networks (DSNs) are ad-hoc mobile networks that include sensor nodes with limited computation and communication capabilities. DSNs are dynamic in the sense that they allow addition and deletion of sensor nodes after deployment to grow the network or replace failing and unreliable nodes. DSNs may be deployed in hostile areas where communication is monitored and nodes are subject to capture and surreptitious use by an adversary. Hence DSNs require cryptographic protection of communications, sensor-capture detection, key revocation and sensor disabling. In this paper, we present a key-management scheme designed to satisfy both operational and security requirements of DSNs. The scheme includes selective distribution and revocation of keys to sensor nodes as well as node re-keying without substantial computation and communication capabilities. It relies on probabilistic key sharing among the nodes of a random graph and uses simple protocols for shared-key discovery and path-key establishment, and for key revocation, re-keying, and incremental addition of nodes. The security and network connectivity characteristics supported by the key-management scheme are discussed and simulation experiments presented.

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A key-management scheme for distributed sensor networks

Usually, a proof of a theorem contains more knowledge than the mere fact that the theorem is true. For instance, to prove that a graph is Hamiltonian it suffices to exhibit a Hamiltonian tour in it; however, this seems to contain more knowledge than the single bit Hamiltonian/non-Hamiltonian.In this paper a computational complexity theory of the “knowledge” contained in a proof is developed. Zero-knowledge proofs are defined as those proofs that convey no additional knowledge other than the correctness of the proposition in question. Examples of zero-knowledge proof systems are given for the languages of quadratic residuosity and 'quadratic nonresiduosity. These are the first examples of zero-knowledge proofs for languages not known to be efficiently recognizable.

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The knowledge complexity of interactive proof-systems

Security is important for many sensor network applications. A particularly harmful attack against sensor and ad hoc networks is known as the Sybil attack based on J.R. Douceur (2002), where a node illegitimately claims multiple identities. This paper systematically analyzes the threat posed by the Sybil attack to wireless sensor networks. We demonstrate that the attack can be exceedingly detrimental to many important functions of the sensor network such as routing, resource allocation, misbehavior detection, etc. We establish a classification of different types of the Sybil attack, which enables us to better understand the threats posed by each type, and better design countermeasures against each type. We then propose several novel techniques to defend against the Sybil attack, and analyze their effectiveness quantitatively.

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The Sybil attack in sensor networks: analysis & defenses

Pairwise key establishment is a fundamental security service in sensor networks; it enables sensor nodes to communicate securely with each other using cryptographic techniques. However, due to the resource constraints on sensors, it is infeasible to use traditional key management techniques such as public key cryptography and key distribution center (KDC). To facilitate the study of novel pairwise key predistribution techniques, this paper presents a general framework for establishing pairwise keys between sensors on the basis of a polynomial-based key predistribution protocol [2]. This paper then presents two efficient instantiations of the general framework: a random subset assignment key predistribution scheme and a grid-based key predistribution scheme. The analysis in this paper indicates that these two schemes have a number of nice properties, including high probability (or guarantee) to establish pairwise keys, tolerance of node captures, and low communication overhead. Finally, this paper presents a technique to reduce the computation at sensors required by these schemes.

Establishing pairwise keys in distributed sensor networks

The problem we deal with in this paper is the research of upper and lower bounds on the randomness required by the dealer to set up a secret sharing scheme. We give both lower and upper bounds for infinite classes of access structures. Lower bounds are obtained using entropy arguments. Upper bounds derive from a decomposition construction based on combinatorial designs (in particular, t-(v, k, λ) designs). We prove a general result on the randomness needed to construct a scheme for the cycle C n; when n is odd our bound is tight. We study the access structures on at most four participants and the connected graphs on five vertices, obtaining exact values for the randomness for all them. Also, we analyze the number of random bits required to construct anonymous threshold schemes, giving upper bounds. (Informally, anonymous threshold schemes are schemes in which the secret can be reconstructed without knowledge of which participants hold which shares.)

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On the dealer's randomness required in secret sharing schemes

Over the last years, research efforts have led the way to embed computation into the environment. Much attention is drawn to technologies supporting dynamicity and mobility over small devices which can follow the user anytime, anywhere. The Bluetooth standard particularly fits this idea, by providing a versatile and flexible wireless network technology with low power consumption. 
 
In this paper, we describe an implementation of a novel framework named JXBT (JXME over Bluetooth), which allows the JXME infrastructure to use Bluetooth as the communication channel. By exploiting the JXME functionalities we can overcome Bluetooth limitations, such as the maximum number of interconnectable devices (7 according to the Bluetooth standard) and the maximum transmission range (10 or 100 meters depending on the version). To test the lightness of JXBT, we designed and evaluated BlueIRC, an application running on top of JXBT. This application enables the set up of a chat among Bluetooth-enabled mobile devices, without requiring them to be within transmission range.

A Bluetooth-based JXME infrastructure

Over the last years, research efforts have led the way to embed computation into the environment. Much attention is drawn to technologies supporting dynamicity and mobility over small devices which can follow the user anytime, anywhere. The Bluetooth standard particularly fits this idea, by providing a versatile and flexible wireless network technology with low power consumption.

In this paper, we describe an implementation of a novel framework named JXBT (JXME over Bluetooth), which allows the JXME infrastructure to use Bluetooth as the communication channel. By exploiting the JXME functionalities we can overcome Bluetooth limitations, such as the maximum number of interconnectable devices (7 according to the Bluetooth standard) and the maximum transmission range (10 or 100 meters depending on the version). To test the lightness of JXBT, we designed and evaluated BlueIRC, an application running on top of JXBT. This application enables the set up of a chat among Bluetooth-enabled mobile devices, without requiring them to be within transmission range.

Information hiding techniques allow a player to hide secret information in some innocent-looking document. In this paper we present a novel approach to information hiding. We investigate the possibilityof embeddinginformation usingthe intrinsicentropyof some classes of cover-documents. In particular we provide algorithms for embedding any binary string in an image mosaic (i.e. an image consisting of a mosaic of smaller images). The algorithms presented allow different levels of security for the information hidden in the cover-document. We also show some techniques to reduce the amount of information the users have to secretly store.

Hiding Information in Image Mosaics

Mobile devices should allow users to exploit services anytime, without any place restriction and in a transparent way. The Bluetooth technology achieves this feature, by providing services at a low cost and with a low power consumption. In a few years, most of the devices accessing the web services will be mobile. In this paper, we evaluate performance of a framework allowing a Java application programmer to directly interface Web Services from a mobile device using a Bluetooth connection. Our work focuses on enhancing Web Services' range of action, presenting a proof of concept of how Web Services-based application can use Bluetooth technology as communication channel. Furthermore, our work is also dedicated to allow the framework to use all the different settings and connection modalities provided by Bluetooth technology. This paper evaluates the usability and efficiency of the framework in a real scenario using mobile devices with limited resources

Carlo Blundo

Papers

On the dealer's randomness required in secret sharing schemes

A Bluetooth-based JXME infrastructure

A Bluetooth-based JXME infrastructure

Hiding Information in Image Mosaics

Performance evaluation of web services invocation over Bluetooth