People don’t choose secure passwords, and they don’t generally use different
passwords for secure (online banking) vs insecure (mailing lists)
authentication. Public-private key cryptography is even more of a hassle for
the average person. However, now that ‘plug-n-work’ connection technologies
like USB and FireWire are fairly pervasive, and products like this USB Drive are available, it
should be fairly simple to build something that works as a ‘data key’ much like
a car or door key does. A device small enough to fit on a keyring would be
unobtrusive enough to take everywhere, and people understand physical keys, so
the learning curve would be minimal. Just plug it into your PC to ‘unlock’ your
data. It could work for encrypting your personal data on disk as well as for
sending secure messages. Even (by today’s standards) moderate storage capacity
(say 64 Mb) could store hundreds of contact details, including public keys, so
sending encrypted email could become much more transparent.
Just some thoughts that occurred while I was reading ‘Java Cryptography’.