*3.1. Privacy Goals*

An SM collects the energy consumption from home appliances usually after a 15 min duration. An SM then generates a consumption report and sends it to the utility company. There might be an adversary peeking at energy consumption of a smart home that can further predict the lifestyle and routine of a homeowner. This poses a threat to security as well as privacy of the smart home. Therefore, to preserve privacy and security, energy consumption is encrypted either at the appliance level or before it leaves the HAN. The energy consumption sent by the HAN is further processed and the CC receives energy consumption details from various SMs. Each meter reports either its own consumption or an aggregation technique is used to sum-up the consumption reports from all meters in a sub-region/zone and send a bulk consumption report after the aggregation. Based on this, the CC generates monthly bills and maintains a profile picture of that region to show that how much electricity consumption is required [44]. The CC continuously collects consumption details from different devices. The received consumption is encrypted or aggregated because if an intruder changes the message, it could easily be identified [20]. This section describes various privacy goals.
