how to get a secure unique identifier from multiple pieces of hardware using python?

Question

Say I have a hundred(possibility thousands) of connected raspberry pi and these pi will emit a message though tcpip to a mongo data base when they get online. This message will be a unique id that will register the device inside of mongodb.

Question: is there a unique number that is secure that I can just emit to a database as a unique id or will there have to be some kind of back and forth?

Answer 1

To identify the PI(s), I'd use/send the serial number(s) ( cat /proc/cpuinfo ) . It's used to make money, so the manufacturer won't tolerate duplicates.

See "Getting Your Raspberry Pi Serial Number Using Python" for Python and further background.

The MAC address identifies a component that could change (eg WiFi dongle).