In the world of rapid technological development there is a need to design new, safer and faster cryptosystems. Security of classical asymmetric cryptosystems such as RSA, Diffie-Hellman key exchange, Elgamal cryptosystem, or cryptosystems using elliptic curves is based on the difficulty of factoring integers and on the difficulty of the discrete logarithm problem respectively. Since for both of these problems there exist efficient quantum algorithms (Shor 1994, Proos & Zalka 2003), the advent of quantum computers will render these systems unsafe. On the other hand, security of the NTRUEncrypt asymmetric cryptosystem is based on the difficulty of the shortest vector and of the closest vector problems in integer lattices, for which no efficie...