Difference between Security in Bluetooth low energy and BR/EDR

Question

This is a basic questiion but I am not able to know it.. I have read the spec but still I am not clear.. My question is that In bluetooth low energy, we use Short term and long term keys in security. What are the differences between them? and also please tell me are these keys used in BR/EDR too? Thanks in advance..

Answer 1

Short Term Key (STK) is used as the first step for encryption (just after pairing is completed). Once a link is encrypted, Long Term Key ( LTK ) is then generated.

Basically, if master doesn't have an LTK generated against a slave, and the same slave attempts to connect again to master, the master assumes that the slave is not authenticated and hence attempts to pair again with the slave. If LTK is present, master understands that this device is already authenticated and proceeds for session encryption.