AbstractA great security of information for the e‐business applications is required. In such applications, use of cryptographic methods is very necessary. The two popularly used cryptographic methods are secret key cryptosystem and public key cryptosystem. Data encryption standard is the most popular secret key cryptosystem. Rivest–Shamir–Adleman algorithm is the most widely used public key cryptosystem. Secret key ciphers are faster than the public key ciphers. But security of public key ciphers is more than that of secret key ciphers. Simulation speed of Nth degree‐truncated polynomial ring units (NTRU) is greater than that of Rivest–Shamir–Adleman algorithm. Also, NTRU requires smaller memory space. Therefore, in order to construct a very secure and high speed cryptosystem, it is required to optimize the NTRU cryptosystem with respect to simulation time. In this paper, NTRU is optimized using advanced optimization techniques, that is, genetic algorithm, particle swarm optimization (PSO) algorithm, and ant colony optimization algorithm. Also, the complexity of NTRU and optimized NTRU using genetic algorithm, ant colony optimization, and PSO algorithms are calculated and compared. It is found that the complexity of NTRU using PSO is the highest as compared with other optimization techniques. Copyright © 2016 John Wiley & Sons, Ltd.