OTD question

1) What security modes are used ? What security levels are used if LE supported ?
2) What pairing mechanism is used ?
3) How is the Link key generated, transmitted and authenticated ? Is Secure Authenticated used (encryption) 

Please refer to the following link:

https://e2e.ti.com/blogs_/b/connecting_wirelessly/archive/2016/08/11/how-bluetooth-4-2-can-help-enable-product-security 

https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/t/404236

Thanks a lot. I notice that this reference is used for New BLE-stack 2.2 which only support for CC2640/CC2650. But now I use CC2541 for development. Is CC2541 covered by this reference?

The CC2540/41 will not support BLE 4.2 due to the increased security features required.

I want to know about what Security mode CC2541 now is using? I found that there is a encryption OAD can be used in CC2541

CC2541 uses AES-128. Please refer to the following link to get more details about encryption OAD:

http://processors.wiki.ti.com/index.php/SerialBootLoader#Encrypted_Bootloading

http://processors.wiki.ti.com/images/8/82/OAD_for_CC254x.pdf

Hope this will help.

What about the pairing mechanism?

BTW: there is an error when i enter the following link

http://processors.wiki.ti.com/index.php/SerialBootLoader#Encrypted_Bootloading

Please try it again or try to use another browser. I could open the link now.