Enhancing Security in NOMA-Based Networks: An Effective Deceptive Approach to Thwart Multiple Eavesdroppers

Securing non-orthogonal multiple access (NOMA) networks against eavesdropping attacks is crucial to deliver reliable communications services. To encounter such a menace, we propose a novel security solution that differs from conventional methods like artificial noise (AN) and friendly jammers. We suggest that for each legitimate user, the base station (BS) divides its signal into a specific number of sub-signals. Therefore, the number of superposed signals increases and creates the illusion for the attacker that the number of users increases as well. Subsequently, this limits legitimate signal overhearing and misleads eavesdroppers into attacking a different target, thwarting their attempts. We analyze our method for single eavesdropper (SE) and multiple non-cooperative eavesdroppers (NCE) attacks and provide closed-form expressions for the outage probability (OP), ergodic capacity, and symbol error probability (SEP). Numerical results show the efficiency of our method over conventional NOMA.