*1.3. Our Contributions*

The communication that makes up the grid smart is one of the obstacles that the smart grid deployment faces. To date, several schemes have been proposed and review surveys have been published, for example, [10–14]. Most of these schemes highlight either communication, technology standards, and infrastructure or home energy managemen<sup>t</sup> and security. To the best of our knowledge, however, privacy is a big issue that still has to be thoroughly examined.

Since the smart grid is designed to facilitate its consumers, keeping the privacy of end users in a HAN is important. To date, a few schemes have been proposed, such as [15–23] to create a safe communication route over vulnerable public networks. These schemes are aimed at establishing a framework that can potentially protect end users' privacy. The majority of the plans cover the smart grid in basic terms, but they leave out smart homes and HANs. As it runs in the field, a HAN is the most vulnerable to cyber threats, theft, and data tampering. Because a consumer may be unaware of cyber security standards, it is critical to have built-in security to protect HANs from various cyber threats. In short, the issues associated with smart homes are rarely explored in published articles. This paper discusses smart homes and gathers the prominent articles in this domain, and proposes a novel privacy preserving scheme. Here, we highlight the following points:


The remainder of the paper is laid out as follows: The smart home is introduced in Section 2. Section 3 discusses the notion of privacy, its parameters, goals and attacks, and

the threats to privacy. Section 4 presents a comparative analysis of advanced privacypreserving techniques, including their benefits and drawbacks, as well as countermeasures. Section 5 describes a privacy-preserving data aggregation technique for fault-tolerant smart homes. Section 6 examines the proposed scheme's security measures, followed by a performance evaluation in Section 7. Future study directions are discussed in Section 8, and the work is concluded in Section 9.

### **2. Smart Home**

A smart home consists of an SM and various appliances. Appliances may be a low voltage devices or high voltage devices which aggregate their energy consumption and send information to SMs, as shown in Figure 1. The SM receives energy consumption from appliances and forward to utilities for further processing [24,25]. Home energy management system (HEMS) is an automated system consist of hardware and software which controls and monitors the various devices and their operations. Users manually manage and control the electricity generation and production [26]. Different hourly block rates are offered for 24 h. Needless devices are automatically turn off with a short notification. Demand side management, demand response, direct load control, real time pricing, time of use, and real time peak pricing are recent examples of HEMS [27].

**Figure 1.** A home area network.
