A cost-efficient one time password-based authentication in cloud environment using equal length cellular automata

One time password (OTP) scheme has been suggested as an efficient and simple solution for authentication in cloud computing. This paper investigates the nature of characteristics polynomials of Equal Length Cellular Automata (ELCA) and its application in OTP generation for authentication in cloud computing. In this work, primitive characteristics polynomial is identified as a crucial criterion for pseudo-randomness of ELCA cycles generated with linear rules. Novel algorithms are also designed for (i) cost effective generation of OTPs, (ii) flexible generation of equally populated OTP sets, and (iii) generation of controllable number of passwords in OTP sets. Application of linear rules in synthesis of OTPs ensures easy implementation using only modular arithmetic, which makes the proposed method truly cost efficient.