[extropy-chat] PGP (was RE: Love of paradox)

[Lee Corbin]

Hal writes

> I got into my own field of cryptography largely because it is founded
> on paradox.  I well remember the astonishment I felt when I first learned
> about public-key cryptography from Martin Gardner's Scientific American
> column back in the 1970s.  Two people can exchange messages such that
> each message is heard by an eavesdropper, yet after a few exchanges and
> some simple mathematics, they can send a secret message from one to the
> other and there is no way the eavesdropper can read it.  When you first
> hear it, it sounds completely impossible and crazy.  If the eavesdropper
> can hear everything, it would seem there is no way the two people can
> transfer any kind of secret.  Yet the RSA algorithm and others have
> proven highly practical and effective.

The Diffie-Hellman key exchange allows this (admittedly surprising)
bypassing of the eavesdropper. Public key cryptography is really
yet another add-on, I thought.

Lee