We have designed and deployed a system that uses X.509 public-key certificates (PKC) and attribute certificates (AC) for access control. This includes an authorization service for...
ded abstract of this work will appear in Public Key Cryptography — PKC 2012. This is the full version. We propose a general framework that converts (ordinary) signature schemes ...
In a practical system, a message is often encrypted more than once by different encryptions, here called multiple encryption, to enhance its security. Additionally, new features ...