Bill Frantz wrote:
[EMAIL PROTECTED] (Ed Gerck) on Monday, June 2, 2008 wrote:

To trust something, you need to receive information from sources OTHER than the source you want to trust, and from as many other sources as necessary according to the extent of the trust you want. With more trust extent, you are more likely to need more independent sources of verification.

In my real-world experience, this way of gaining trust is only
really used for strangers. For people we know, recognition and
memory are more compelling ways of trusting.

Recognition = a channel of information
memory = a channel of information

When you look at trust in various contexts, you will still find the need to receive information from sources OTHER than the source you want to trust. You may use these channels under different names, such as memory which is a special type of output that serves as input at a later point in time.

The distinguishing aspect between information and trust is this: "trust is that which is essential to a communication channel but cannot be transferred from a source to a destination using that channel". In other words, self-assertions cannot transfer trust. "Trust me" is, actually, a good indication not to trust.

We can use this recognition and memory in the online world as well.
SSH automatically recognizes previously used hosts. Programs such
as the Pet Names Tool <>
recognize public keys used by web sites, and provide us with a
human-recognizable name so we can remember our previous
interactions with that web site. Once we can securely recognize a
site, we can form our own trust decisions, without the necessity of
involving third parties.

Yes, where recognition is the OTHER channel that tells you that the value (given in the original channel) is correct. Just the value by itself is not useful for communicating trust -- you also need something else (eg, a digital sig) to provide the OTHER channel of information.

Ed Gerck

The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]

Reply via email to