# Performance Analysis of Quantum Key Distribution Technology for Power Business
## 1 Introduction  
The power Internet of Things (IoT) revolves around all aspects of the power system, fully applying modern information technologies such as artificial intelligence, mobile interconnection and advanced communication technologies to achieve interconnection of all things and human-computer interaction in all aspects of the power system [1]. The ecological environment of power industry is being changed to form an interactive power grid interconnected by traditional power systems, distributed energy sources and information and communication systems. By analyzing the incidents of power system attacks in the world in recent years (e.g., man-in-the-middle attack, data exposure and code instrumentation), the continuous deterioration of the network environment and the rapid evolution of network attack technologies have further highlighted the importance of power information communication security [2; 3; 4]. With the rapid construction of power IoT, the security of data interaction between power systems depends on the adopted security protection mechanism. Although the information encryption mechanisms of different power systems are different, the commonality is that the security of the key directly affects the safe operation of the power system. Currently, there are two main ways to update the power system key: online and offline, respectively. Some power dispatching and control businesses mainly rely on offline way to update the key, which leads to the insecure and insufficient timeliness of key distribution. Most management businesses use the online key updatemethod; endless network attack methods make key distribution face the hidden danger of being stolen. Once a key is obtained by the third party, its attack will cause serious threat to the power system [5; 6]. As a new method to ensure the secure transmission of information, QKD technology has attracted the attention of all walks of life and has successively carried out verification tests in many fields. It uses the physical characteristics of photons to solve the problem of online secure distribution of keys and realizes the anti-theft and tamper-proof of keys. QKD technology can greatly improve information security in the fields of national defense, government affairs, finance, power and energy [7; 8; 9]. The implementation of projects such as the United States defense advanced research projects agency QKD network in 2005, the European secure communication based on quantum cryptography network in 2008, and the Tokyo QKD network in Japan in 2010 marked that this technology has become one of the key technologies for development [10; 11; 12]. Since 2012, various countries have proposed plans to build QKD networks. In 2015, China launched the construction of a QKD network spanning 2000 km (Beijing-Shanghai Trunk Line), which has been piloted in banking and national defense [13]. The banking industry has carried out security transmission of business data, such as data disaster preparedness, information collection and public opinion confidentiality. China Telecom has built Shanghai Lujiazui financial QKD network, improving the protection ability of user data. In order to ensure the safe transmission of privacy data, many local governments have constructed the QKD network of e-government. However, compared with the line environment and business scenarios of power industry, the existing QKD application mode is single, and the quantum channel is dominated by buried optical fiber cable (BOFC), which is less affected by the external environment. Therefore, it is difficult to provide effective reference for special industries. Since 90% of power communication networks are overhead lines, with long distances between stations and a large number of nodes, QKD performance is easily affected by environmental factors such as wind, rain, snow and electromagnetism [14; 15]. Several researches on the application of QKD in power industry have been carried out. A QKD scheme that was independent of line polarization had achieved good results in wide area power network [16].