  In this paper, we utilize the potential offered by multidimensional separable
states (MSS) for secure and simultaneous distributions of keys in a layered
network. We present protocols for both quantum and semi-quantum key
distribution and discuss their robustness against various eavesdropping
strategies. We provide a procedure to identify the requisite resource states to
generalise these protocols for arbitrary layered networks. Finally, we study
the interrelation between the local dimensionalities of states and achievable
key rates in a given layer. These proposals are realisable with current
technology, thanks to employment of MSS and many advances in generation,
manipulation and measurement of higher-dimensional orbital angular momentum
states of light.
