Patent ID: 6216231
Filing Date: 2001-04-10
Classification: G06F

Abstract:
A method for system security in distributed systems, said method comprising the steps of:a) making authentic statements by trusted intermediaries;b) deriving freshness constraints from initial policy assumptions and the authentic statements; andc) imposing freshness constraints by employing recent-secure authenticating principals to effect revocation;wherein said step b) comprises the substep I) of normalizing suffix constraints of the freshness constraint prior to applying other rules; andwherein said substep I) comprises applying the following axiom,(A.fwdarw.B notbefore t.sub.1 notafter t.sub.2).OR left.(((t.sub.1.ltoreq.t.sub.3).LAMBDA.(t.sub.4.ltoreq.t.sub.2)).OR left.A.fwdarw.B notbefore t.sub.3 notafter t.sub.4).