"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

To give you a preview of IEEE Pervasive Computing's October-December special issue on wearable computing, this installment of Notes from the Community focuses on submissions about wearables. The topics range from the origins of wearable computing to unusual examples of wearables, and from emerging uses to wearables in popular culture.

http://ieeexplore.ieee.org/iel7/7756/6818495/06818508.pdf

Wearable Computing

In everyday meetings, automatic association of co-located mobile devices would ease sharing of web-links, media, and other information. We propose a method that compares patterns of silence from device microphones to detect co-location of those devices. This method works with unsynchronized audio capture, requires only 100bps and preserves privacy. We show how to formulate pattern matching in a sequential hypothesis framework so that changes in co-location status (when people leave or join a meeting) can be determined promptly, and how to compute the likelihood ratio in practice. Using 16 hours of captured audio, we show that our approach can correctly determine device co-location with a low error rate of 0.05%, and can detect co-location changes 10 seconds faster than a similar decision rule based on a constant time window. Compared to a prior audio signature method, we achieve higher accuracy at 1/7 the bit rate.

Determining co-location using a sequential hypothesis test on patterns of silence

This installment of Notes from the Community covers smart assistants, AI, autonomous vehicles, user interfaces, striking views of our future, and outrageous designer strollers.

Views of Current and Future Technology

Welcome to the inaugural column of Notes from the Community! This column offers a curated summary of interesting news and research in pervasive and mobile computing, with content drawn from submissions from community members and readers Visit wwwredditcom/r/pervasivecomputing to join the discussion

What's New in the Ubicomp Community?

Peer-to-peer systems are vulnerable to attrition attacks that include both traditional, network-level denial of service attacks as well as application-level attacks in which malign peers conspire to waste loyal peers’ resources. We describe a set of defenses for the LOCKSS digital preservation system that help ensure that applicationlevel attacks even from powerful adversaries are less effective than network-level attacks, and that network-level attacks must be intense, wide-spread, and prolonged to impair the system.

Mary Baker

Papers

Wearable Computing

Determining co-location using a sequential hypothesis test on patterns of silence

Views of Current and Future Technology

What's New in the Ubicomp Community?

Resisting Attrition Attacks on a Peer-to-Peer System