We show how single system steering can be exhibited by classical light, a feature originating from superposition in classical optics that also enables entanglement and Bell-violation by classical light beams. Single system steering is the temporal analogue of Einstein-Podolsky-Rosen (EPR) steering in the quantum domain, enabling control of the state of a remote system, and can hence be connected to the security of secret key generation between two remote parties. We derive the steering criterion for a single mode coherent state when displaced parity measurements are performed at two different times. The security bound of the Bennett-Brassard 1984 (BB84) protocol under the gaussian cloning attack is calculated to yield an, in principle, ideal and quantum-like key rate using a fine-grained uncertainty relation corresponding to the classical phase space.
@article{arxiv.1606.08273,
title = {Classical light steering leading to quantum-like security},
author = {Tanumoy Pramanik and Archan S. Majumdar},
journal= {arXiv preprint arXiv:1606.08273},
year = {2016}
}