Potentially long, off-topic message: (follow-ups and/or flames probably best
kept private :)
"Ihnen, David" wrote:
Would you consider PGP more than a low-effort? It would be zero effort if
we weren't concerned about the privacy of our own secret keys, thus keeping
them encrypted behind passwords.
Personally? Using PGP is very low-effort for me. Typing my 25+ character
passphrase has become reflexive. I've run a site re: PGP use since my first
website in 1993 or so, so I'm probably not a good test-case. :-)
Maybe an extra-low-effort system would consist of a simply speaking a
keyword into a microphone, and using voiceprint authentication to decrypt
the secret keys. Fortunately almost all computers have the ability to read
in decent quality audio. Sending to particular people is no effort - the
public key aquisition can be automated.
I saw some very interesting matrix-mapping software back in 1994 and 1995 for
DOS that converted individual words (expandable to phrases) into vectors
(stored as matrices) that could easily be compared against a stored file for
each person. The idea was to do the "opposite" of voice-to-text recognition
software and store the portion of audio that is unique for each user instead of
using primarily the part that is similar.
Its interesting to think of the change in load on list servers. Would you
encrypt to the list server, who then decrypts and re-encrypts for each
client, or would there be a collaborative key for the list that everybody
had the secret to and could decrypt? More probably we would just
cleartext-sign the messages for source authentication, for backwards
compatibility, I suspect.
Assuming, like the original 'open letter' poster, that you don't want others to
snoop on the messages (but their being a subscriber to the list is "okay"),
then you'd want a public key for the mailing list that all messages are
encrypted to. The mailing list would decrypt the session key for the message
(PGP only requires using CPU intensive P.K. cryptography to sign a session
key). It would then re-encrypt the session key (effectively, the message) to
the public keys of each of the recipients on the list. (It would not need to
necessarily verify the sender's signature, to avoid decrypting messages at
all). The sender's signature (if used) would be intact in the encrypted
message and each person would be able to verify for themselves that that user
had sent 'them' the message in question. The CPU intensive portion would be
encrypting the session keys to everyone on the list. Assuming the old PGP
protocol, that would mean doing 1024 (or more) bit RSA on a 128 bit session key
(16 bytes).
Either way, it can be zero-effort for the people generating the e-mail,
outside of authenticating your personal secret key, though accepting the
e-mail has the same effort problems.
I would be signing my messages pgp, if I could, but I haven't gotten ahold
of PGP 7 yet... and the earlier versions don't work on 2000.
Use any version of PGP or "PGP for Windows" and use the clipboard encryption
features:
1) select all text (Ctrl-A)
2) "copy" (Ctrl-C)
3) click on PGP tray icon
4) click "sign encrypt"
5) enter password
6) click window of program with selected text
7) "paste" (Ctrl-V) (replacing original with encrypted + signed cipher-text)
