unfortunately several of these professional seals are only a bit more obscure, but not much harder to open than a zip tie.<p>Introduction to Tamper Evident Devices from datagram at defcon 19 <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=W07ZpEv9Sog" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=W07ZpEv9Sog</a> is interesting to watch