Delegation of access rights in a privacy preserving access control model

Delegation is a process of sharing access rights by users of an access control model. It facilitates the distribution of authorities in the model. It is also useful in collaborative environments. Despite the advantages, delegation may have an impact on the access control model´s security. Allowing users to share access rights without the control of an administrator can be used by malicious users to exploit the model. Delegation may also result in privacy violations if it allows accessing data without the data provider´s consent. Even though the consent is taken, the privacy can still be violated if the data is used differently than the data provider agreed. Our work investigates data privacy in delegation. As a contribution, a privacy model is introduced that allows a data provider setting privacy policies that state how their data should be used by different organizations or parties who are interested in their data. Based on this setting, a delegation model is designed to consider the privacy policies in taking delegation decisions and also, to set the data usage criteria for the access right receivers. In addition to privacy policies, several delegation policies and constraint have been used to control delegation operations. Delegation is studied within a party and between two parties.