| Survivable
Ad Hoc Networks
Fall 2002 This is a weekly research seminar on Survivable Ad Hoc Networks, organized by Profs. Agnes Chan, Guevara Noubir and Rajmohan Rajaraman. Students with interests in cryptography, distributed algorithms, networking, or security are encouraged to attend. Students attending the seminar are expected to read research papers, actively participate in discussions, and make presentations. Time & Location: Thursday, 10:30 - 12:00AM @ CN 149 Contact: Mailing-List: crypto_seminar@lists.ccs.neu.edu
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October 10, 2002 Hector Ho Fuentes Topic: A Survey on Public Key Certificate Revocation Abstract: Public Key Infrastructures allow users to
authenticate and exchange information with other users by using less keys
than Symmetric Key Infrastructures. But one of the main problems
in Public Key Infrastructures is to revoke keys. In a Symmetric Key
case, only two parties are involved, thus revocation of the key is relative
easy, because the notification is only to the two parties involved.
But in a Public Key Infrastructure, all the users of the system need to
be notified, but also now each key needs to be validated before use, to
make sure it has not been revoked. Thus it is very important to create
efficient ways to validate or revoke Public Key in Certificates.
Several mechanism have been proposed, each with its advantages and disadvantages.
In the talk we will cover some basic information about public key infrastructures
and the proposed mechanisms for certificate revocation. (full paper .ps
)
October 17, 2002 Tansel Kaya Topic: Adaptive multi-route computing in wireless ad hoc networks Abstract: I will present the problem of adaptively
computing multiple paths to transmit a large volume of data from a source
S to a destination D in an ad hoc wireless network. In this framework,
the distribution of data is performed in both the spatial and temporal
domain. During the communication of a source-destination pair in an ad
hoc wireless network, if an intermediate node moves out of range, the operation
of the network will be disturbed. This will result in route re-discoveries
or the invocation of path maintenance algorithms, which will cause the
end-to-end delay to increase. In the framework I am going to present, while
data is transmitted, route re-discoveries are performed before route errors
occur. This creates a series of multiple paths during data transfer, which
are used for sending packets consecutively. The possible improvement observations
are as follows: Single-path routing algorithms do not ensure optimal end-to-end
delay. If a set of paths can be found between the source and destination,
it is possible to improve end-to-end delay by distributing the data and
sending it through selected multi paths. This is a widely used approach
for wired networks but hasn't been often applied to ad-hoc networks. This
approach reduces congestion and end-to-end delay. The solution methods
for this problem are Lagrange Relaxation and Subgradient Heuristics.
October 24, 2002 Richard Jia Topic: Energy-conserving techniques for communication in wireless ad hoc networks Abstract: Energy efficiency is an important issue
in wireless ad hoc networks, and is becoming a desirable metric for algorithm
& protocol design. This is because wireless ad hoc devices are battery-powered,
and technical improvement in battery capacity is relatively slow, compared
with the fast-growing ad hoc network applications. Among the various components
in an ad hoc device, transceiver is probably the largest contributor in
energy consumption. Since operations in ad hoc networks are generally communication-oriented,
energy efficient protocols are thus desired. In this talk, I will give
an overview of the existing techniques for energy conservation in wireless
ad hoc networks that has been proposed in recent years.
October 31, 2002 Guolong Lin Topic: Provable Security Abstract: Based on my recent reading, I will try to deliver the concept of provable security, which is a new buzz word in theoretical cryptography. The talk will consist of three parts, the first part will motivate the concept; the second give the definition of provable security; and the last part will have some examples on the application of the concept. Basic knowledge of cryptography is assumed. The talk is based on notes from Bellare, et al. November 7, 2002 Feng Zhu Topic: Security in wireless ad hoc networks Abstract: Security is an important issue in routing protocols for wireless ad hoc networks. The talk will consist of two part. The first part will introduce some known threats to routing protocols for ad hoc networks. The second one will include some secure routing protocols for ad hoc networks. A collection of papers on Ad Hoc Network Security November 14, 2002 Jiangzhuo Chen Topic: Energy-efficient scheduling in wireless ad hoc networks Abstract: Energy efficiency is critical to the battery-operated systems, e.g. wireless ad hoc networks. Some observations are helpful for energy-efficient scheduling in a wireless environment. Transmission energy can be significantly lowered by transmitting packets over a longer duration. The electro-chemical mechanisms allow batteries to recover energy during idle periods. Based on these, several models are reviewed, in which, offline and online scheduling algorithms are proposed to minimize energy consumptions subject to various constraints. Simulations are run to show that these considerations are important. November 21, 2002 Rajmohan Rajaraman Topic: Sensor networks Abstract:
November 28, 2002 Guevara Noubir Topic: Secure multicast Abstract: |