Karim A. Banawan

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We consider the problem of private information retrieval (PIR) over a distributed storage system. The storage system consists of N non-colluding databases, each storing a coded version of M messages. In the PIR problem, the user wishes to retrieve one of the available messages without revealing the message identity to any individual database. We derive the(More)
We consider the problem of single-round private information retrieval (PIR) from N replicated databases. We consider the case when B databases are outdated (unsynchronized), or even worse, adversarial (Byzantine), and therefore, can return incorrect answers. In the PIR problem with Byzantine databases (BPIR), a user wishes to retrieve a specific message(More)
We consider the problem of multi-message private information retrieval (MPIR) from N non-communicating replicated databases. In MPIR, the user is interested in retrieving P messages out of M stored messages without leaking the identity of the retrieved messages. The information-theoretic sum capacity of MPIR CP s is the maximum number of desired message(More)
We consider the problem of multi-message private information retrieval (MPIR) from N non-communicating replicated databases. In MPIR, the user is interested in retrieving P messages out of M stored messages without leaking the identity of the retrieved messages. The information-theoretic sum capacity of MPIR CP is the maximum number of desired message(More)
We consider the multiple-input multipleoutput (MIMO) wiretap channel under a minimum receiver-side power constraint in addition to the usual maximum transmitterside power constraint. This problem is motivated by energy harvesting communications with wireless energy transfer, where an added goal is to deliver a minimum amount of energy to a receiver in(More)
We consider the two-user multiple-input multipleoutput (MIMO) interference channel with confidential messages (ICCM). We determine the exact sum secure degrees of freedom (s.d.o.f.) for the symmetric case of M antennas at both transmitters and N antennas at both receivers. We develop the converse by combining the broadcast channel with confidential messages(More)
We consider the multiple access wiretap channel (MAC-WTC), where multiple legitimate users wish to have secure communication with a legitimate receiver in the presence of an eavesdropper. The exact secure degrees of freedom (s.d.o.f.) region of this channel is known. Achieving this region requires users to follow a certain protocol altruistically and(More)
We consider the problem of private information retrieval (PIR) fromN non-colluding and replicated databases when the user is equipped with a cache that holds an uncoded fraction r from each of the K stored messages in the databases. We assume that the databases are unaware of the cache content. We investigate D∗(r) the optimal download cost normalized with(More)
We consider a channel with N parallel sub-bands. There is a single user that can access exactly k channels, while maintaining some minimum rate at each accessed channel. The transmission takes place in the presence of a jammer which can access at most m channels. We cast the problem as an extensive-form game and derive the optimal power allocation(More)
We consider the multiple-input multiple-output (MIMO) wiretap channel under a minimum receiver-side power constraint in addition to the usual maximum transmitter-side power constraint. This problem is motivated by energy harvesting communications with wireless energy transfer, where an added goal is to deliver a minimum amount of energy to a receiver in(More)