Research On Voice Call Encryption Algorithm Based On Content Association Key

Since the beginning of the 21st century,with the rapid development of Internet communication technology,people's data transmitted through the Internet is not limited to text,images,or audio and video files.It also has higher requirements for the real-time nature of information.At the same time,due to the openness of the Internet itself and people's emphasis on privacy,the security of data transmitted over the Internet has become a top priority.Therefore,future secure communication technology has a very broad application prospect.Compared with the traditional encryption technology,the content-associated key encryption technology has the core advantages of lower computational complexity and the ciphertext that does not contain all the plaintext information.It is more suitable for real-time applications that require high efficiency and security.In voice calls,the Opus format is widely used in network voice call scenarios due to its lower latency and better sound compression rate than other compression formats.Based on the content-associated key encryption technology and chaotic encryption ideas,an encryption algorithm for the Opus audio format in network transmission is designed.The algorithm first analyzes the Opus audio packet format,removes irrelevant file marks and other information in the audio packet,obtains the true audio entity data contained in each Opus audio packet,and then uses an improved Logistic chaotic mapping based on the idea of chaotic block encryption.The location where the content association key is extracted is determined,and the audio entity data after extraction and backfilling is completely covered and encrypted according to the chaotic stream encryption idea,so as to achieve a better encryption effect.And on the Android platform,a wide area network secure call system that uses a content-associated key encryption algorithm for Opus audio is designed and implemented.The system's main call module first uses the native API of the Android system to record the original PCM data,and then compresses it through Opus.The encoder compresses and encodes the PCM data,and then encrypts each Opus audio packet through a content-associated key encryption algorithm,and forwards the encrypted key ciphertext packet through different servers.Finally,a comprehensive analysis of the performance of the algorithm in terms of key space,encryption effect,correlation,and encryption speed is performed to verify the effectiveness of the encryption algorithm.And test and verify the connection rate,key matching rate,voice intelligibility,etc.of the secure call system,which shows that the system has reached the high stability and security that the secure call system should have.