A Study on the Security Vulnerability of Bluetooth Low Energy and Improvement Method

In this paper, we introduce a security vulnerability of Bluetooth Low Energy(BLE) and propose a n improved security method to solve it . BLE is used to transmit and receive data between nodes such as sensors, wearable devices in the Internet of T hings (IoT) environment. However, there is a possibility that an encryption key for communicating between nodes can be cracked because of the security vulnerability of BLE. The s ecurity vulnerability of BLE is that the length of the Temporary Key (TK) to generate the encryption key is too short. It is a fatal problem in terms of a data security. We describe how an attacke r can crack the encryption key through the vulnerability. To solve this problem, we propose an improved security method that increases the length of the TK. In the conventional BLE, the encryption key can be cracked within 20 sec onds . But, it may take 600, 000,000,000 years when the proposed method is used. Therefore, the proposed method can ensure that it is infeasible to crack the encryption key.This work was supported by Basic Science Research Program through the National Research Foundation of K orea(NRF) funded by the Ministry of Education (No. NRF - 2015R1D1A1A01059473