Tuesday, June 08, 2004
Trust Whom?
A great deal of interest is placed these days on the mechanisms whereby trust can be conveyed in a distributed system. I must admit that this problem is one of great interest to me personally, as well as a number of friends of mine. I cannot help but notice, however, that the concept seems much clearer in our daily lives than in the world of the internet. What exactly causes this dichotomy?
One answer is the mathemechanical nature of such systems on the internet. It would a very different world indeed if, when speaking to our friends, we first had to do a number of calculations involving such things as products of prime numbers prior to knowing who was in front of us. This perspective does create another possibility of the nature of the dichotomy that I believe warrants further investigation.
In our daily activities, the subject of trust doesn’t even arise until we know the identity of the recipient. A sentence such as "I trust you, though I have no idea who you are" simply makes no sense. Therefore, it seems that identity is the precondition of trust-- and a precondition we have yet to settle in the world of distributed systems.
The process of ensuring that the identity of an entity in a distributed system is valid is called authentication. This, it seems to me, is the real problem we face in establishing trust. While we have a number of ways by which we can establish credible authentication, they are all subject to probability-- either within the mechanism itself, or within their context outside the system. For example, authentication via the verification of created information that would only be possible with the possession of a private key is, from a mathemechanical perspective, nearly foolproof. From a contextual perspective, however, the issues of key compromise and identity management cloud the issue.
There are a number of things that can be done to mitigate these concerns, though the question of whether they can be eliminated entirely is unclear (and, in my opinion, unlikely). I will discuss these mitigation strategies, and other aspects of the problem that I believe are of interest to the creation of a distributed trust model, in future posts. For now, having framed the problem will have to do.
