Zhaoyu Liu :: Selected Research Projects
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Agent-based trust management for pervasive environments
For pervasive computing systems, how to trust mobile clients such as
devices, users and applications is a great challenge. This project is
trying to provide an answer to this question by introducing an agent-based
automated trust negotiation framework. In this framework, a client
downloads the trust negotiation strategies from the system for the
specific resources and uses the downloaded strategies to negotiate the
trust of the system to access the resources. By using the mobile agents,
Security Capsules, to encode the definition and interpretation of the
trust negotiation strategies, the negotiation strategies can be
distributed and loaded dynamically and transparently. The configurability
and transparency of the Security Capsules make this framework more
flexible, adaptive and dynamic for trust negotiation between various
clients and systems of pervasive environments.
Security for pervasive computing
Pervasive applications should be able to select the proper security
services based on the hardware and environments, without concerns about
the implementation and configuration details. However, most existing
security systems, which are not built for the light, thin devices of
pervasive computing environments, cannot provide quality of protection to
applications. The proposed research will explore a capsule-based security
system to support flexible quality of protection in pervasive
environments. We will develop a model of security as services that
centers on people, instead on devices, for improving the usability of
security. A testbed will be designed and implemented to evaluate and
demonstrate the proposed security system.
Dynamic trust model for mobile ad hoc networks
This project plans to build a trust model for mobile ad hoc networks. In
our model, each node is initially assigned a trust level. Then we use
several approaches to dynamically update trust levels by using reports
from threat detection tools, such as Intrusion Detection Systems (IDSs),
located on all nodes in the network. The nodes neighboring to a node
exhibiting suspicious behavior initiate trust reports. These trust
reports are propagated through the network using one of our proposed
methods. A source node can use the trust levels it establishes for other
nodes to evaluate the security of routes to destination nodes. Using these
trust levels as a guide, the source node can then select a route that
meets the security requirements of the message to be transmitted. This
project demonstrates important concepts for establishing a collaborative,
dynamic trust model and for using this model as an example to enhance the
security of message routing in mobile ad hoc networks.
Security and survivability for mobile ad hoc networks
The nature of mobile ad hoc networks creates an environment susceptible to
various forms of attack and unreliability, in particular, scenarios which
disrupt network communication. Traditional security measures place
emphasis on the reliability of routing information, trust models and
malicious node identification to ensure robust communication.
Historically, the effectiveness of many of these measures has been limited
to the integrity of the information shared between nodes. In this project,
we propose a robust routing methodology using Smart Agents generated by
nodes in mobile ad hoc networks. Our approach provides nodes with the
ability to independently identify non-collaborating regions within their
local network. This information is factored into calculations performed by
agents for identifying robust and direct routes to nodes of interest. The
routing path is created without requiring any prior knowledge of the
network's topology and eliminates the need for nodes to maintain a routing
cache or incorporate trust management for routing purposes. By utilizing
the self-routing, recovery and management capabilities of smart agents,
and our proposed agent-based routing algorithm, we are capable of
attaining robust communication in highly unreliable, non-collaborating
environments while minimizing broadband communication overhead.
Dynamic and flexible security for wireless devices
Existing security systems tend to be static and it is very difficult to
change the security policies and mechanisms once the systems are installed.
With systems that support wireless computing devices, the
fundamental problem is to
provide security that is expressive and flexible enough to satisfy the
specific needs of diverse applications.
During the prior research on dynamic and flexible security for emerging
applications, we developed an agent-based security architecture that is
based on and built into the underlying dynamic digital infrastructure. The
agents, which are innovative Active Capabilities (ACs), are signed mobile
code fragments that are used to specify security policies and mechanisms.
The security architecture is able to 1) support various policies and
mechanisms, 2) add, replace or revoke policies and mechanisms, 3) allow
applications to specify the kind of security guarantees they want from the
system, on the fly, 4) dynamically enforce these customized policies and
mechanisms, and 5) restrict the use of policy to applications and systems
that need to know the policy.
In this project we will identify the security issues in wireless
computing environment, develop an initial conceptual security framework
based on our prior agent-based security architecture, and present
the preliminary experimental results.
Click
here for selected publications
Return to the
research page.
Return to the home page.