Corelab Seminar

Dimitris Sakavalas (NTUA)
Secure Broadcast in Generic and Wireless Networks

Communication networks consist of numerous interacting entities. These entities often wish to collaborate in order to achieve a certain task even if some of them are malicious/corrupted. Such considerations put forth the need for secure distributed computing. It is widely accepted that an integral part of a secure distributed system is a mechanism for reaching ``agreement'' between all non-corrupted parts of a system. One of the major variations of the agreement problem is the "Secure Broadcast" problem, where we assume the existence of a designated participant on whose input value every non-corrupted participant should agree.

The problem has been extensively studied in the standard model where the communication network is assumed to be complete. In the case of incomplete communication networks, research has introduced new parameters for optimization, relative to the network's topology. Moreover topologically restricted corruption models have been considered, and related problems remain open so far. Finally secure Broadcast in wireless networks is considered in this thesis. The structure of wireless networks allows the corrupted entities to cause interference to other receivers, which brings up new challenges regarding their manipulation. On the other hand, participants are committed to perform local broadcasts, which greatly facilitates achieving agreement.