A solution to improving encryption efficiency of DTRU cryptosystem

Abstract

DTRU, a new variant of NTRU public - key cryptosystem, has some advantages in comparison with original NTRU at the same security levels. However, in DTRU, the cipher-text is at least three time longer than the plain-text i.e., message-expansion factor of DTRU is higher than that of other well-known public-key cryptosystems. By modifying encryption procedure, in this paper, we propose a new variant of DTRU, called M-DTRU, that has not only smaller messageexpansion factor but also larger message-security than original cryptosystem.1