Smart Grid (SG) is a modernized power grid. Nowadays changing the power grid system into a smart grid is revolution and evolution. Owing to the widespread use of wireless communication technologies in Advanced Metering Infrastructure (AMI) of SG, security is one of the most significant and challenging problem. A specific feature of AMI systems is that it requires hybrid transmission modes of data which includes unicast, multicast and broadcast communication modes. Moreover, Smart Meters (SMs) and smart home appliances may have limited computing and storage capability and only authorized Home Area Network (HAN) appliances may communicate with SMs. Various key management systems have been presented to address these issues. However, performance and /or security issues are still exist in most of them. To meet these distinctive requirements and ensure confidentiality during communications in HAN of AMI, secure and robust key management scheme is required. This paper proposes a key management scheme tailored for HAN with significantly lower rekeying overhead and enhanced robustness which allows the SM and HAN devices to share a session key between them. In our scheme, when any smart device joins/leaves the system, there is no need to update the keys of existing devices. As a result, the rekeying cost is decreased to\( \mathcal{O}(1) \). Compared with existing key management schemes, the proposed scheme achieves fast key distribution and message transmission between SM and the HAN devices while ensuring the privacy. The results illustrate that our scheme can outperform the related schemes in terms of rekeying cost while ensuring privacy protection.

智能电网（SG）是现代化的电网。如今，将电网系统变成智能电网是革命和进化。由于无线通信技术已在SG的高级计量基础架构（AMI）中得到广泛使用，因此安全性是最重要且最具挑战性的问题之一。AMI系统的一个特殊功能是它需要数据的混合传输模式，包括单播，多播和广播通信模式。此外，智能电表（SM）和智能家电可能具有有限的计算和存储能力，并且只有授权的家庭局域网（HAN）设备才能与SM通信。已经提出了各种密钥管理系统来解决这些问题。但是，大多数情况下仍然存在性能和/或安全问题。为了满足这些独特的要求并在AMI的HAN中进行通信时确保机密性，需要安全而强大的密钥管理方案。本文提出了一种针对HAN量身定制的密钥管理方案，该方案具有显着降低的密钥开销和增强的鲁棒性，从而使SM和HAN设备可以共享它们之间的会话密钥。在我们的方案中，当任何智能设备加入/退出系统时，都不需要更新现有设备的密钥。结果，密钥更新成本降低到 当任何智能设备加入/退出系统时，无需更新现有设备的密钥。结果，密钥更新成本降低到 当任何智能设备加入/退出系统时，无需更新现有设备的密钥。结果，密钥更新成本降低到\（\ mathcal {O}（1）\）。与现有的密钥管理方案相比，该方案在确保隐私的同时，实现了SM与HAN设备之间的快速密钥分发和消息传输。结果表明，在确保隐私保护的同时，我们的方案在重新输入密钥费用方面可以胜过相关方案。