Current collaborative tools are often not able to profit from existing systems for user management. It is therefore necessary for collaborative systems to administrate their users ...
In this paper, a practical and secure e-mail system (called “PractiSES”) that performs public key distribution and management in a unique way is proposed. PractiSES is a networ...
At Eurocrypt’91, Chaum and van Heyst introduced the concept of group signature. In such a scheme, each group member is allowed to sign messages on behalf of a group anonymously. ...
This paper presents a model of hierarchical organization of Certification Authorities which can be applied to any open system network. In order to study the feasibility of the pro...
In this paper, we propose a new efficient and secure micro-payment scheme, named e-coupons, which can provide the users the facility of delegating their spending capability to oth...