Sec. Requirements for Sophisticated Web Use

We would like to use WWW for....

Sharing sensitive information with particular groups of individuals

==> Authentication of Entities
==> Access Control / Authorization

Exchanging, publish info in a trustworthy manner: proposals, reports, ...

==> Authentication of Data (Signed Messages/Documents)

Digital payment: Buying and selling goods, services, information

==> Authentication in Transactions (payment validation)

Also, in ALL of these situations, we would like to be able to achieve

==> Data Privacy, Integrity

These abilities require secure communications between authenticated agents