In the first part of the talk we study the secrecy rate and outage probability in Multiple-Input-Single-Output (MISO) Gaussian wiretap channels in the presence of a large number of legitimate users and eavesdroppers. In particular, we analyze the asymptotic achievable secrecy rates and outage, when only statistical knowledge on the wiretap channels is available to the transmitter.
The analysis provides exact expressions for the reduction in the secrecy rate as the number of eavesdroppers grows, compared to the boost in the secrecy rate as the number of legitimate users grows.
In the second part of the talk we discuss secure group testing. Group Testing (GT) aims at identifying a small subset of “defective” items from a large population, by grouping items into a small number of test pools. The test outcome of a pool is positive if it contains at least one defective item, and is negative otherwise. GT algorithms are utilized in many applications, and privacy regarding the status of the items, namely, defective or not, is a critical issue.
In this study, we consider a scenario where there is an eavesdropper which is able to observe a subset of the GT outcomes (pools). We propose a new non-adaptive Secure Group Testing (SGT) algorithm based on information theoretic principles, which keeps the eavesdropper ignorant regarding the items status.
Joint work with Asaf Cohen, Joseph Kampeas and Alejandro Cohen.