But if that's not enough for you, then there's two things you can do:1. Use PGP encryption to create shell PGP encryption, this is easy to do conceptually if you know PGP, but confusing.Introducing our guests, Alice and Bob.1.1 Alice and Bob send each other their public keys.1.2 Alice and Bob verify all communications from here on out by using signed PGP messages.1.3 After the first signed PGP handshake is accomplished, they exchange new PGP messages   that contain entirely new public keys for Alice and Bob.1.4 They then have two options.1.4.1 They can repeat this action over set time periods e.g. once per month/week to stall any brute force attack1.4.2 They can use One Time Only public keys. Simply, they use new public keys for every single communication either of them makes period. Every encrypted message also contains a public key for the next message. This is as close to impregnable as I know how. It means that any attacker can never rely on previous information obtained. The only realistic methods of attack are side channel (keylogging etc) or a PGP exploit, see above for details. This is like a "come at me with your quantum computer, bro" operation. It's also a pain in the ass to manage all those PGP keys, but I guess you could write software to do it on the fly seamlessly and correctly each time (hint).2. Or you could simply exchange symmetric keys via PGP signed messages. Symmetric encryption can be orders of magnitude more powerful than PGP at less computationally cost. We're talking encryption it could take centuries or millennia to crack with brute force here. The disadvantage is that you cannot possibly give out those keys to anybody, they are always secret, there is no public key with symmetric encryption. But... by using the strengths of public key crypto, you can use PGP to share the secret keys and thus obtain super strong encryption with ease.-- Paranoid Pine