*4.5. Observations*

This section highlights various shortcomings of the schemes discussed under data aggregation, CIA triad and anonymity, user authenticity, and key management. According to the findings, some issues are at hardware level and we need an international standard for the equipment used for the deployment of smart grids. Moreover, the hardware cost is another issue whereby the most important is that a majority of the proposed schemes discuss only one problem—e.g., authenticity or key management—and ignore other features, especially in the HAN context. If a proposed scheme does not consider the HAN model or some of the threads, then during the implementation phase of the smart grid, it can bring a number of severe issues such as cyber security concerns at the application level.
