Is there a way to uniquely identify players in MC:PE?

I'm thinking about hosting a small MC:PE server using the PocketMine server platform.

However, I need to be able to uniquely identify players for various purposes. Does MC:PE/PocketMine offer any way to do this?

I don't think vanilla mcpe does, as you're able to change your username at will. However, you could use a server mod/plugin that makes players register a username with a password, and type the password when they join before being allowed to use commands, build, etc.

EDIT: You can use the SimpleAuth plugin with PocketMine. It "requires registration of player names using a password. That blocks faked usernames and using admin accounts."