This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

"bad MIC" when sniffing?

I want to sniff the connection between a Bluetooth Low Energy mouse (Logitech MX Master) and my smartphone (Samsung Galaxy Alpha). To do this I have tried to use the nRF-Sniffer in combination with an nRF51-DK as well as an nRF52-preview-DK board (compatible hex file was provided by Aryan here). My operating system is Windows 7 Enterprise (64 bit), Wireshark version is 1.12.6.

Sniffing the initial connection is working as expected, but after a couple of seconds all packets are marked with an error: "Encrypted packet decrypted incorrectly (bad MIC)". I'm not a Bluetooth expert (yet), but I think that the sniffer should be able to decrypt all packets as he is listening to the connection from the very beginning. Traces are attached to this post. What am I doing wrong? Isn't it possible to sniff the communication for a longer time?

Trace with nRF51-DK: Logitech_MX_Samsung_Alpha_nrf51.pcapng

Trace with nRF52-preview-DK: Logitech_MX_Samsung_Alpha_nrf52.pcapng

Update (August 17): In the meantime I have reproduced this observation on a Linux system using the Python API. The effect is probably related to the board itself (or the software it is running), not the host computer.

Parents Reply Children
No Data
Related