Research On Application Of Bluetooth Low Energysecurity Connectivity Mechanism And Algorithm

With the promulgation of the Bluetooth 4.0 specification core, Bluetooth Low Energy technology officially released, and it has been widespread concern. Compared with traditional Bluetooth, Bluetooth Low Energy has extremely low power consumption and fast connection, it has been widely applied to wearable devices, medical equipments, smart phones, tablet computers and other electronic devices. More information is transmitted and shared by Bluetooth Low Energy. Therefore, the Bluetooth Low Energy security is vital. However, domestic research on Bluetooth security still remains in the traditional Bluetooth stage. For these reasons, the paper researched Bluetooth Low Energy connectivity mechanism and Advanced Encryption Standard(Advanced Encryption Standard, AES) algorithm which is used by Bluetooth Low Energy.Through analysis of Bluetooth Core Specification V4.0 and summary of the security of Bluetooth Low Energy connectivity mechanism, including: security protection functions, security model and pairing, authentication, bonding, detailed encryption process. Meanwhile, the AES algorithm design principles, design theories, encryption and decryption processes are summarized description. Based on the analysis of common attack methods Bluetooth and AES algorithms, make further analysis of the security risks of Bluetooth Low Energy connectivity mechanism and the AES algorithm, and analyze the AES algorithm S-box mathematical properties and key expansion algorithm, design a new security mechanism of Bluetooth Low Energy connectivity, and apply the connectivity mechanism on the CC2541 Bluetooth Low Energy development platform based BLE-Stack protocol stack and operating system OSAL.The innovation in this paper is to strengthen the security of Bluetooth Low Energy in the application layer and strengthen the security of the AES algorithm in the mathematical properties. In the Bluetooth Low Energy application layer by providing encryption broadcast, random PIN code, mandatory pairing, confirm button and the secondary encryption improve their security. In the AES algorithm, increase the item number of S box algebraic expression to the most 255, the period of affine transformation to to the most 16, the period of iterative output to to the most 256, while improve the key expansion algorithm to prevent derivation to forward and backward round keys, thus strengthen the security strength of AES algorithm, and the algorithm is applied to Bluetooth Low Energy application layer.