This book is rooted in the thesis that complexity theory is extremely rich in conceptual
content, and that this contents should be explicitly communicated in expositions and courses …

Blockchain, as one of the crypto-intensive creatures, has become a very hot topic recently.
Although many surveys have recently been dedicated to the security and privacy issues of …

Although this may seem a paradox, all exact science is dominated by the idea of
approximation. Bertrand Russell (1872-1970) Most natural optimization problems, including …

Publicly accessible databases are an indispensable resource for retrieving up-to-date
information. But they also pose a significant risk to the privacy of the user, since a curious …

But, perhaps, we should start with a few words about graphs in general. They are, of course,
one of the prime objects of study in Discrete Mathematics. However, graphs are among the …

For several NP-complete problems, there have been a progression of better but still
exponential algorithms. In this paper, we address the relative likelihood of sub-exponential …

We show that every language in NP has a probablistic verifier that checks membership
proofs for it using logarithmic number of random bits and by examining a constant number of …

Approximation algorithms have developed in response to the impossibility of solving a great
variety of important optimization problems. Too frequently, when attempting to get a solution …

We give a new characterization of NP: the class NP contains exactly those languages L for
which membership proofs (a proof that an input x is in L) can be verified probabilistically in …

We present a polynomial time approximation scheme for Euclidean TSP in fixed dimensions.
For every fixed c> 1 and given any n nodes in ℛ2, a randomized version of the scheme finds …