The most dangerous terrorists have probably already reverted to couriers with one-time pads. One-time pads are uncrackable, yet they were used extensively before modern cryptography was even invented. They&#x27;re cumbersome and constrained but very effective. No amount of mass surveillance will alter their efficacy.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;One-time_pad" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;One-time_pad</a>