The shortened form of this key's npub. For example, npub1sdnq9yr3kwzaauhylwty6ttnum6zgcf34s0lwcythjcew8zss8fqlm45zq becomes sdnq9yr3:fqlm45zq, being the first 8 (after npub1) and the last 8 with a colon between.
npub1sdnq9yr3kwzaauhylwty6ttnum6zgcf34s0lwcythjcew8zss8fqlm45zq
sdnq9yr3:fqlm45zq