NTRU was first introduced by J. Hoffstein, Pipher and J.H Silverman in 1998. Its security, efficiency compactness properties have been carefully studied for more than two decades. A key encapsulation mechanism (KEM) version even submitted to the NIST standardization competition made it final round. Even though has not chosen be a new standard, remains relevant, practical trustful post-quantum c...

This paper explores some attacks that someone with a Quantum Computer may be able to perform against NTRUEncrypt, and in particular NTRUEncrypt as implemented by the publicly available library from Security Innovation. We show four attacks that an attacker with a Quantum Computer might be able to perform against encryption performed by this library. Two of these attacks recover the private key ...

Finding the shortest vector of a lattice is one of the most important problems in computational lattice theory. For a random lattice, one can estimate the length of the shortest vector using the Gaussian heuristic. However, no rigorous proof can be provided for some classes of lattices, as the Gaussian heuristic may not hold for them. In the paper we study two types of random lattices in crypto...

Acknowledgements I should thank many people who have helped me on the way of writing and then righting what you read now. I start with my family, whose love and support have been the very foundation of all my studies. I thank Professor Buchmann, who interested me in the field of lattice cryptography and arranged this thesis. I thank my first supervisor Christoph Ludwig, for many talks about lat...

The security and privacy issues regarding outsourcing data have risen significantly as cloud computing has grown in demand. Consequently, since management been delegated to an untrusted server the phase, access control identified a major problem storage systems. To overcome this problem, paper, of using Attribute-Based Access Control (ABAC) approach is utilized. First, must be stored strong for...