Abstract
Abstract: Many commercial and financial activities in the real-life require reliable mechansisms to provide accountability for the transactions that has been executed. If electronic commerce aim to substitute or support similar activities in the electronic world, it has to provide the same degree of accountability. Despite this requirement is crucial, we observe that many existing security mechanisms and protocols are not designed by considering accountability as a fundamental property. In this paper, we show that this is true, particularly in the case of delegation protocols. Then to address the problem, we explicitly introduce accountability in delegation by defining a new semantics and by designing a new protocol that help to eliminate this lack of accountability.