Research On Lightweight Data Encryption Scheme Of Body Area Network Based On Chaotic System

In recent years,wireless body area network(WBAN)has become one of the effective technical means to implement telemedicine monitoring.Physical sign data can be collected by sensors placed on the body surface or implanted,and transmitted to the background through the gateway,which greatly reduces the medical cost and can be applied to the early prevention and detection of diseases.Since the sign information transmitted in WBAN belongs to personal privacy and is used to judge the condition,it must be transmitted safely in the public channel.Any form of tampering or hacking may cause serious consequences to users.However,the computing power,power consumption and volume of the sensor limit the security protection strength of WBAN.Therefore,reducing the computational complexity and ensuring the security of the system is the key problem to be solved urgently in the current body area network.In the IEEE.802.15.6 standard for wireless body area networks,the data security of WBAN needs data encryption.However,the computational complexity and implementation power consumption of traditional encryption algorithms are difficult to meet the environment with limited computing power.Moreover,the data types in the body area network are complex,including not only simple text data such as body temperature,blood oxygen and blood pressure,but also two-dimensional signals and image data such as ECG and EEG.The importance of the data is also different.In view of the above background,a scheme to generate a stream of cryptographic sequences with natural randomness using a chaotic system with a small amount of computation,easy to implement and control is proposed in this paper.Considering the possible dynamic degradation effect of chaotic system in digital environment,an optional encryption accuracy scheme is adopted,and different encryption accuracy is selected with reference to data sensitivity to ensure data security.At the same time,for the problem that the fixed-point chaos cannot calculate the Lyapunov exponent and other key indicators characterizing the chaotic characteristics,the spectral entropy(SEN)is used as the reference for the degradation of fixed-point chaotic dynamics,and the degradation degree of chaotic dynamics is intuitively measured by comparing the spectral entropy of floating-point number and fixed-point number.A multi precision data encryption scheme applied to body area network is proposed.The analysis of the system shows that the fixed-point chaos can effectively reduce the computational complexity of the system and meet the requirements of real-time transmission in body area network.To deal with the chaotic dynamic degradation effect of single chaotic fixed-point system,the single chaotic fixed-point system is improved.Based on the same amount of calculation,the hybrid chaotic system is introduced.The random interference mode is added to prevent the system from entering the pseudo chaotic orbit and maintain the randomness of the sequence.In the test analysis part,the sequence generated by the proposed fixed-point 32-bit system has passed the NIST test,which shows that the fixed-point sequence is also a random sequence.The security test and analysis of heterogeneous combined chaotic encryption system show that the scheme can effectively resist common means such as violence analysis and differential attack,and has well security performance.