As sensor networks edge closer towards wide-spread deployment, security issues become a central concern. So far, the main research focus has been on making sensor networks feasible and useful, and less emphasis was placed on security. We design a suite of security...

... This paper introduces Smart Packets and describes the Smart Packets architecture, the packet formats, the language and its design goals, and security considerations.

Abstract. We present a model of steganographic systems which allows to evaluate their security. We especially want to establish an analogy to the known-plaintext-attack which is commonly used to rate cryptographic systems. This model’s main statement is that the embedding operation of a steganographic system should work indeterministic from the attacker’s point of view. This is proved by means of information theory. Key words. Security and modeling of steganography, entropy, indeterminism, secret communication, hidden communication 1 A Short Introduction to Steganography Bruce Schneier characterizes steganography in the following way [1]: “Steganography serves to hide secret messages in other messages, such that the secret’s very existence is concealed. ” He also states some historic examples, such as “…invisible inks, tiny pin punctures on selected characters, minute differences between handwritten characters,

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Abstract. We study the problem of broadcasting confidential information to a collection of n devices while providing the ability to revoke an arbitrary subset of those devices (and tolerating collusion among the revoked devices). In this paper, we restrict our attention to low-memory devices, that is, devices that can store at most O(log n) keys. We consider solutions for both zero-state and low-state cases, where such devices are organized in a tree structure T. We allow the group controller to encrypt broadcasts to any subtree of T,evenifthetreeisbasedonanmulti-way organizational chart or a severely unbalanced multicast tree. 1

Abstract — Initial work in ad hoc routing has considered only the problem of providing efficient mechanisms for finding paths in very dynamic networks, without considering security. Because of this, there are a number of attacks that can be used to manipulate the routing in an ad hoc network. In this paper, we describe these threats, specifically showing their effects on AODV and DSR. Our protocol, named Authenticated Routing for Ad hoc Networks (ARAN), uses public-key cryptographic mechanisms to defeat all identified attacks. We detail how ARAN can secure routing in environments where nodes are authorized to participate but untrusted to cooperate, as well as environments where participants do not need to be authorized to participate. Through both simulation and experimentation with our publicly-available implementation, we characterize and evaluate ARAN and show that it is able to effectively and efficiently discover secure routes within an ad hoc network. I.

. This paper presents and discusses the idea of Web-based volunteer computing, which allows people to cooperate in solving a large parallel problem by using standard Web browsers to volunteer their computers ' processing power. Because volunteering requires no prior human contact and very little technical knowledge, it becomes very easy to build very large volunteer computing networks. At its full potential, volunteer computing can make it possible to build world-wide massively parallel computing networks more powerful than any supercomputer. Even on a smaller, more practical scale, volunteer computing can be used within companies or institutions to provide supercomputer-like facilities by harnessing the computing power of existing workstations. Many interesting variations are possible, including networks of information appliances (NOIAs), paid volunteer systems, and barter trade of compute cycles. In this paper, we discuss these possibilities, and identify several issues ...

We propose two new instructions, swperm and sieve, that can be used to efficiently complete an arbitrary bit-level permutation of an n-bit word with or without repetitions. Permutations with repetitions are rearrangements of an ordered set in which elements may replace other elements in the set; such permutations are useful in cryptographic algorithms. On a 4-way superscalar processor, an arbitrary 64-bit permutation with repetitions of 1-bit subwords can be completed in 11 instructions and only 4 cycles using the two proposed instructions. For subwords of size 4 bits or greater, an arbitrary permutation with repetitions of a 64-bit register can be completed in a single cycle using a single swperm instruction. This improves upon previous permutation instruction proposals that require log(r) sequential instructions to permute r subwords of a 64-bit word without repetitions. Our method requires fewer instructions to permute 4-bit or larger subwords packed in a 64-bit register and fewer execution cycles for 1-bit subwords on wide superscalar processors.

This paper discusses interoperability of digital rights management (DRM) systems. We start by describing a basic reference model for DRM. The cause of interoperability is served by understanding and circumscribing what DRM is “in the whole. ” Then we outline and contrast three different approaches to achieving interoperability. One approach relies on flexible network services to provide functionality where it is needed, perhaps by bridging different systems. We describe an experimental service orchestration system (NEMO) that enables such an approach. Keywords—Digital media distribution, digital rights management (DRM), standards, trusted computing, Web services. I.

Public-key cryptography is fast becoming the foundation for online commerce and other applications that require security and authentication in an open network. The widespread use of public-key cryptography requires a public-key infrastructure to publish and manage public-key values. Without a functioning infrastructure, public-key cryptography is only marginally more useful than traditional, secret -key cryptography. This thesis presents a set of characteristics that are common to all public-key infrastructures. These criteria are intended to encapsulate the fundamental issues that arise when dealing with such systems. They can be used both as a "shopping list" for those who need to choose an infrastructure for a particular application, and as a guide for infrastructure developers, that they may be more aware of any compromises or tradeoffs they might make in their work. The characteristics are used to present a survey of current and some proposed infrastructure systems. The criteria...