# A Hybrid Encryption Scheme for Quantum Secure Video Conferencing Combined with Blockchain
###### Abstract  
Traditional video conference systems depend largely on computational complexity to ensure system security, but with the development of high-performance computers, the existing encryption system will be seriously threatened. To solve this problem, a hybrid encryption scheme for quantum secure video conferencing combined with blockchain is proposed in this study. In the system solution architecture, first, the quantum key distribution network is embedded in the classic network; then, the \"classical + quantum\" hybrid encryption scheme is designed according to the secret level required for the video conference content. Besides, the real-time monitoring module of the quantum key distribution network is designed to ensure that users can check the running state of the network at any time. Meeting minutes can be shared by combining with blockchain. In order to quickly query meeting minutes, a cache-efficient query method based on B+ tree is proposed. The experimental results show that compared with the traditional video conference system, the quantum secure video conference system sufficiently integrates the technical advantages of the quantum key distribution to resist the security threats such as channel eavesdropping and high-performance computational attacks while ensuring the stable operation of the classic system, thus providing a video conference system with a higher security level. Meanwhile, the query time cost of blockchain with different lengths is tested, and the query efficiency of the proposed method is 3.15-times higher than the original query efficiency of blockchain. v 2022103390/math107307  
2022103390/12/202210390/1  
algorithm with a variable bandwidth was designed by [PERSON] et al. [2]. By analyzing the resource allocation of the video conference system according to different priority levels, the QoS control framework was designed with the OpenDayLight lithium-based controller [3]. In video conferences, military intelligence, business secrets, classified information, personal privacy, etc., are often involved in conference contents. Therefore, people are paying more and more attention to the security of video data and the instantaneity of transmission. According to the pseudo-randomness of the chaotic sequence cipher, the chaotic cipher generation algorithm was improved by using a two-dimensional time-varying discrete space-time system, and then, the video frame was encrypted by XOR with the new pseudo-random key stream, which improved the security and real-time performance of network multimedia video files [4]. [PERSON] [5] applied wavelet transform technology to video scrambling encryption and, at the same time, used chaotic keying technology to increase the amount of keys and improve the parallelism of algorithms, so as to improve the security and real-time performance of video encryption. [PERSON] et al. [6] used the chaotic sequences generated by a quantum cellular neural network to initialize the chaotic map of logistics, generated the chaotic sequence, and then, repeated bitwise operations to obtain enough keys to solve the problem of large video coding delay after the chaotic video encryption algorithm. Pseudo-random sequences were generated based on the spatiotemporal lattices, which were used for the encryption and decryption key of the image or video file [7]. According to two chaotic maps, a secure pseudo-random number generator was designed, and a binary sequence was generated by this pseudo-random number generator [8]. Reference [9] proposed an alternative video encryption algorithm, in which the key is generated pseudo-randomly by the ChaCha algorithm. The H.264/A VC encoding algorithm encodes the video into multiple slices; the key semantic elements in the slice can be selectively encrypted; the key is generated by a pseudo-random generator and updated in real-time [10].