Division of Computer and Network Systems (CNS)

Randomization has proved to be a vital part in building essentially any kind of secure cryptographic system: secret keys should be randomly generated and most cryptographic primitives, such as encryption, must be probabilistic. As a common abstraction, it is typically assumed that ideal randomness is available to all the participants of the system. In many situations, this assumption is highly unrealistic, and cryptographic systems have to be built based on *imperfect* sources of randomness.

Secure applications require trustworthy hardware for successful deployment. A trustworthy hardware device (e.g., a smart card) should maintain its security properties even against efforts at probing and reverse engineering; moreover, sensitive data stored on a trustworthy hardware device should be protected at all times. Side-channels attacks are used to learn the secrets stored by a device through monitoring the side effects of its computation. The well known power side-channel attack uses the effect that a cryptographic key has on the power waveform as the cipher runs.

This research project focuses on the development of cryptographic mathematical models and constructions that address realistic security requirements at the implementation level. This is a fundamental problem as cryptographic security formalisms are often criticized for lack of relevance given the wide range of attacks available at the implementation level.

Information and Communications Technology (ICT) infrastructure failures and cyber attacks are realities that can have catastrophic societal effects. Information Assurance (IA) can be defined as the operations undertaken to protect and defend ICT systems by ensuring their dependability and security. There is a critical need for systematic IA methods that enable ICT systems to adapt and survive any type of disruption or attack. A major hurdle in the development of IA techniques is the lack of models and metrics which enable one to determine the effectiveness of IA mechanisms.

It is critical to protect the Internet from attacks such as denial of service, and attacks on inter-domain routing. Although several defenses have been proposed, actual deployments have been limited. A primary reason for this lack of deployment is that most defenses have not been validated under realistic conditions, or at sufficiently large scales. Many attacks also have second-order effects that are not well understood. This is because it is difficult to incorporate all the protocols involved at any reasonable scale in analytical, simulation, or emulation models or testbeds.