Axelrod’s “Evolution of Cooperation” studies extremely simple individuals in an environment which provides incentives both to cooperate and to cheat. In broad circumstances, it turns out that simple traits of trustworthiness will dominate in an evolving population. With more complex individuals it becomes necessary to recognize members of a behavior group and incentives arise to signal that you are a member of the group even if you are not.
Trust between humans may arise from a perception of character in the person to be trusted. In other cases one might trust an institution that has manifest a clear business plan to deserve trust. I suppose that this is the original reason that banks built imposing buildings. Some advertising is designed to induce trust. Bonding agents can produce synthetic but useful trust arrangements.
Some people are naturally inclined to trust authority whereas others are just as inclined to distrust it. Hierarchical Certificate Authorities (PKI) appeal to those inclined to authority. Others scoff. Ellison gives independent reasons to doubt hierarchical schemes. Schemes such as PGP’s trust web attract the some, but one must be wary of synthetic webs. Those comments apply as well to “key signing parties” as favored by some in the PGP community. Trust is very messy. It is tempting to assume that it is transitive.
To trust an individual or institution, two things are normally required:
Someone noted that he would trust his money but not his children to his banker, while he would trust his children but not his money to his mother-in-law. I wish my bank were more savvy on authentication.
There are many properties that you might trust a program to have. Some of these pages are concerned with trusting that a program will not abscond with our secrets. We do not consider here the issue of trusting the code to produce correct answers except to the extent that security helps correctly written code work correctly by preventing interference from other code.