nrf51822 password on characteristic

[Foxek]

Good evening. I write a project on nrf51822 in which there are a number of services with a set of characteristics (write and read). I need to limit access to some characteristics with a password. Is it possible?

[endnode]

You can do whatever you want on APP layer so if you define protocol on top of that Characteristic and implement some password verification the it will work. On BLE level you have only Security Manager methods which restrict access to certain (G)ATT objects as per link (encrypted/unencrypted) status but that is global for the link and GATT Server, you cannot make it more granular and define some additional PINs or passwords for each object...

[endnode]

Just to complete: if you are not using encrypted link that using passwords is useless because anyone with 40$ equipment will hear it in 20-100m diameter. If you are using properly secured link then why would you protect one part of the client from another when it must come from the same device? And if you don't trust each other then fine, deploy proper secure channel based on symmetric or asymmetric keys and not passwords, that should have died in 80s...