I think the way it would work is that the boss himself would send the signature somehow (e.g. on teams) and bosses that don't want their businesses to fall vict

I think the way it would work is that the boss himself would send the signature somehow (e.g. on teams) and bosses that don't want their businesses to fall victim would have to ensure that their employees would never accept a call from them outside of the system that allowed the signature check.