Risks to the Public

It is a maxim of sound computer-security practice that a cryptographic key should have only a single use. For example, an RSA key pair should be used only for public-key encryption or only for digital signatures, and not for both.In this paper we show ...

A timed-release cryptosystem allows a sender to encrypt a message so that only the intended recipient can read it only after a specified time. We formalize the concept of a secure timed-release public-key cryptosystem and show that, if a third party is ...

A convertible authenticated encryption scheme allows a designated receiver to recover and verify a message simultaneously, during which the recipient can prove the dishonesty of the sender to any third party if the sender repudiates her signature later. ...