An Interdomain PKI Model Based on Trust Lists

The penetration of PKI technology in the market is moving slowly due to interoperability concerns. Main causes are not technical but political and social since there is no trust development model that appropriately deals with multidomain PKIs. We propose a new architecture that on one hand considers that trust is not an homogeneous property but tied to a particular relation, and on the other hand, trust management must be performed through specialized entities that can evaluate its risks and threads. The model is based on trust certificate lists that allows users to hold a personalized trust view without having to get involved in technical details. The model dynamically adapts tothe context changes thanks to a new certificate extension, we have called TrustProviderLink (TPL).

Prices versus exams as strategic instruments for competing universities

In this paper we investigate the optimal choice of prices and/or exams by universities in the presence of credit constraints. We first compare the optimal behavior of a public, welfare maximizing, monopoly and a private, profit maximizing, monopoly. Then we model competition between a public and a private institution and investigate the new role of exams/prices in this environment. We find that, under certain circumstances, the public university may have an interest to raise tuition fees from minimum levels if it cares for global welfare. This will be the case provided that (i) the private institution has higher quality and uses only prices to select applicants, or (ii) the private institution has lower quality and uses also exams to select students. When this is the case, there are efficiency grounds for raising public prices