  Non-Orthogonal Multiple Access (NOMA) has been recognized as one of the most
significant enabling technologies for future wireless systems due to its
eminent spectral efficiency, ability to provide an additional degree of freedom
for Ultra Reliable Low Latency Communications (URLLC) and grant free random
access. Meanwhile, Physical Layer Security (PLS) has got much attention for
future wireless communication systems due to its capability to provide security
without relying on traditional cryptography based algorithms. In this article,
security design requirements for NOMA and solutions provided by PLS to fulfill
these requirements are discussed. The merits and challenges arising from
employing PLS to NOMA are identified. Finally, future recommendations and
prospective solutions are also presented.
