Corelab Seminar
				2012-2013
				Dimitris Sakavalas (NTUA)
                                             
				Secure Broadcast in Generic and Wireless Networks
                                          
				
				Abstract. 
               
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.
 
