>How do you prove that Bob leaked the information? How do you prove that Abe told Bob? Data watermarks, small changes (little tiny bits) that allows to track t

>How do you prove that Bob leaked the information? How do you prove that Abe told Bob? Data watermarks, small changes (little tiny bits) that allows to track the leaks. Also audit logs, you know who has what, etc. The topic has been hotly discussed with GDPR as the leaks have rather harsh consequences (beside being dragged through the mud, erm newspapers).