Maximum Passkey Length

[adityaj]

As per my requirement, I need strong pairing mechanism, i am referring ble_app_gls example of nRF5_SDK_15.2.0_9412b96 sdk for checking pairing. As i have seen in the code, only 6 bytes passkey are used.
Can we increase the Passkey Length? If yes, how can we do that?

[Vidar Berg]

Hi, 

The passkey must be 6 digits (0-9) according to the Bluetooth specification. You can read more about the Pairing methods in Bluetooth core specification v.5, vol. 3, part H, section 2.3.  I don't think it's feasible to perform a MITM attack if you use LE secure connections pairing (LESC).