Abstract
Internet of Things has revolutionized the ways and means of use and management of electric grid systems. Now, the old mechanical grids are equipped with smart devices that not only automate the traditional grid but enable two way communications between the user and power suppliers called smart grid. Although, a lot of protocols have been developed to enable a secure communication between suppliers and consumers, cyber-physical systems (CPSs) are prone to privacy issues where adversaries may have access to particular users' information. In this article, an anonymous orthogonal code-based privacy preserving scheme, named ALPHA, is proposed for CPSs. The CPS is considered as a basic unit of the modern smart grid, which aggregates the power consumption from smart devices by keeping the user information confidential, anonymous, and untraceable. The proposed scheme, ALPHA, uses orthogonal bit codes and a systematized method to authenticate and manage the anonymity and untraceablity of user data along with low communication and computation overheads.