We prove lower bounds for the direct sum problem for two-party bounded error randomised multipleround communication protocols. Our proofs use the notion of information cost of a p...
—Consider the following Simultaneous Message Passing (SMP) model for computing a relation f ⊆ X ×Y ×Z. In this model Alice, on input x ∈ X and Bob, on input y ∈ Y, send o...
Abstract. We propose a way to establish peer-to-peer authenticated communications over an insecure channel by using an extra channel which can authenticate very short strings, e.g....
Assume that two distant parties, Alice and Bob, as well as an adversary, Eve, have access to (quantum) systems prepared jointly according to a tripartite state ρABE. In addition, ...
Matthias Christandl, Artur Ekert, Michal Horodecki...
Perfectly secret message transmission can be realized with only partially secret and weakly correlated information shared by the parties as soon as this information allows for the ...