Make Seeds Expire in TOTP Authentication

Time-based One-Time Password (TOTP) is commonly used in many digital services to meet the increasing demands of security in user authentication. The security of TOTP owes much to the management of TOTP seeds from which onetime passwords are computed, but there is a certain risk of the leakage of TOTP seeds in practice. This study aims to bring a mechanism that virtually realizes the expiration of TOTP seeds. Even if a seed is left unattended or exposed to somebody at a certain point in time, the seed expires as time passes. The mechanism is developed by using the logistic map, together with careful control of numeric values that is necessary to avoid issues caused by finite-precision calculations. The paper sketches the proposed scheme and introduces the results of numerical investigations for discussing choices of good parameters.