"A Survey of Mobility Models for Ad Hoc Network Research," Wireless Comm. & Mobile Computing (WCMC) : Special issue on Mobile Ad Hoc Networking : Research

In the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models, and realistic movements of the mobile users (i.e., a mobility model). This paper is a survey of mobility models that are used in the simulations of ad hoc networks. We describe several mobility models that represent mobile nodes whose movements are independent of each other (i.e., entity mobility models) and several mobility models that represent mobile nodes whose movements are dependent on each other (i.e., group mobility models). The goal of this paper is to present a number of mobility models in order to offer researchers more informed choices when they are deciding upon a mobility model to use in their performance evaluations. Lastly, we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Specifically, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated.

/pdf/a-survey-of-mobility-models-for-ad-hoc-network-research-ygkxat400x.pdf

A survey of mobility models for ad hoc network research

We study the problem of searching on data that is encrypted using a public key system. Consider user Bob who sends email to user Alice encrypted under Alice’s public key. An email gateway wants to test whether the email contains the keyword “urgent” so that it could route the email accordingly. Alice, on the other hand does not wish to give the gateway the ability to decrypt all her messages. We define and construct a mechanism that enables Alice to provide a key to the gateway that enables the gateway to test whether the word “urgent” is a keyword in the email without learning anything else about the email. We refer to this mechanism as Public Key Encryption with keyword Search. As another example, consider a mail server that stores various messages publicly encrypted for Alice by others. Using our mechanism Alice can send the mail server a key that will enable the server to identify all messages containing some specific keyword, but learn nothing else. We define the concept of public key encryption with keyword search and give several constructions.

https://link.springer.com/content/pdf/10.1007%2F978-3-540-24676-3_30.pdf

Public Key Encryption with Keyword Search

We consider routing security in wireless sensor networks. Many sensor network routing protocols have been proposed, but none of them have been designed with security as a goal. We propose security goals for routing in sensor networks, show how attacks against ad-hoc and peer-to-peer networks can be adapted into powerful attacks against sensor networks, introduce two classes of novel attacks against sensor networks sinkholes and HELLO floods, and analyze the security of all the major sensor network routing protocols. We describe crippling attacks against all of them and suggest countermeasures and design considerations. This is the first such analysis of secure routing in sensor networks.

/pdf/secure-routing-in-wireless-sensor-networks-attacks-and-4630unozk9.pdf

Secure routing in wireless sensor networks: attacks and countermeasures

As sensor networks edge closer towards wide-spread deployment, security issues become a central concern. So far, much research has focused on making sensor networks feasible and useful, and has not concentrated on security.We present a suite of security building blocks optimized for resource-constrained environments and wireless communication. SPINS has two secure building blocks: SNEP and mTESLA SNEP provides the following important baseline security primitives: Data confidentiality, two-party data authentication, and data freshness. A particularly hard problem is to provide efficient broadcast authentication, which is an important mechanism for sensor networks. mTESLA is a new protocol which provides authenticated broadcast for severely resource-constrained environments. We implemented the above protocols, and show that they are practical even on minimal hardware: the performance of the protocol suite easily matches the data rate of our network. Additionally, we demonstrate that the suite can be used for building higher level protocols.

http://www.csl.mtu.edu/cs5461/www/Reading/Perrig02.pdf

SPINS: security protocols for sensor networks

A secure timeline is a tamper-evident historic record of the states through which a system goes throughout its operational history. Secure timelines can help us reason about the temporal ordering of system states in a provable manner. We extend secure timelines to encompass multiple, mutually distrustful services, using timeline entanglement. Timeline entanglement associates disparate timelines maintained at independent systems, by linking undeniably the past of one timeline to the future of another. Timeline entanglement is a sound method to map a time step in the history of one service onto the timeline of another, and helps clients of entangled services to get persistent temporal proofs for services rendered that survive the demise or non-cooperation of the originating service. In this paper we present the design and implementation of Timeweave, our service development framework for timeline entanglement based on two novel disk-based authenticated data structures. We evaluate Timeweave's performance characteristics and show that it can be efficiently deployed in a loosely-coupled distributed system of a few hundred services with overhead of roughly 2-8% of the processing resources of a PC-grade system.

Secure History Preservation Through Timeline Entanglement

We report on a wearable digital diary study of 26 participants that explores people’s daily authentication behavior across a wide range of targets (phones, PCs, websites, doors, cars, etc.) using a wide range of authenticators (passwords, PINs, physical keys, ID badges, fingerprints, etc.). Our goal is to gain an understanding of how much of a burden different kinds of authentication place on people, so that we can evaluate what kinds of improvements would most benefit them. We found that on average 25% of our participants’ authentications employed physical tokens such as car keys, which suggests that token-based authentication, in addition to password authentication, is a worthy area for improvement. We also found that our participants’ authentication behavior and opinions about authentication varied greatly, so any particular solution might not please everyone. We observed a surprisingly high (3–12%) false reject rate across many types of authentication. We present the design and implementation of the study itself, since wearable digital diary studies may prove useful for others exploring similar topics of human behavior. Finally, we provide an example use of participants’ logs of authentication events as simulation workloads for investigating the possible energy consumption of a “universal authentication” device.

/pdf/a-study-of-authentication-in-daily-life-46pfbuv2ed.pdf

A Study of Authentication in Daily Life.

This paper evaluates the performance of three popular versions of the UNIX operating system on the x86 architecture: Linux, FreeBSD, and Solaris. We evaluate the systems using freely available micro- and application benchmarks to characterize the behavior of their operating system services. We evaluate the currently available major releases of the systems "asis," without any performance tuning.

Our results show that the x86 operating systems and system libraries we tested fail to deliver the Pentium's full memory write performance to applications. On small-file workloads, Linux is an order of magnitude faster than the other systems. On networking software, FreeBSD provides two to three times higher bandwidth than Linux. In general, Solaris performance usually lies between that of the other two systems.

Although each operating system out-performs the others in some area, we conclude that no one system offers clearly better overall performance. Other factors, such as extra features, ease of installation, or freely available source code, are more convincing reasons for choosing a particular system.

A performance comparison of UNIX operating systems on the Pentium

P2P systems are exposed to an unusually broad range of attacks. These include a spectrum of denial-of-service, or attrition, attacks from low-level packet flooding to high-level abuse of the peer communication protocol. We identify a set of defenses that systems can deploy against such attacks and potential synergies among them. We illustrate the application of these defenses in the context of the LOCKSS digital preservation system.

Impeding attrition attacks in P2P systems

The present invention provides a computer implemented method, comprising the steps of: determining using data from a sensing device, when a moveable obscuring structure is in a closed position. When the obscuring structure is in the closed position, the transmission of accessible images captured by an image capture device at the location of a local user is to remote user locations in a video conference session is prevented.

Mary Baker

Papers

Secure History Preservation Through Timeline Entanglement

A Study of Authentication in Daily Life.

A performance comparison of UNIX operating systems on the Pentium

Impeding attrition attacks in P2P systems

System, method and apparatus for controlling image access in a video collaboration system