What Physical Layer Security Can Do for 6G Security

While existing security protocols were designed with a focus on the core network, enhancement of B5G access network becomes critical importance. Despite strengthening 5G respect to LTE, there are still open issues that have not been fully addressed. This work is articulated around premise rethinking design bottom up, starting at physical layer, only viable in 6G but importantly, arises as an efficient way overcome hurdles novel use cases, notably massive machine type communications (mMTC), ultra reliable low latency (URLLC) and autonomous cyberphysical systems. Unlike review papers treat layer orthogonally cryptography, we will try provide few insights underlying connections. Discussing many practical issues, present comprehensive state-of the-art i) secret key generation from shared randomness, ii) wiretap channels fundamental limits, iii) authentication devices using unclonable functions (PUFs), localization multi-factor authentication, and, iv) jamming attacks layer. We finally conclude proposers' aspirations for landscape, hyper-connectivity semantic era.