From simple message exchanges among friends, to purchases made with a credit card, to the transmission of sensitive documents, the Internet is now being used for many different purposes. However, the presence of malicious users on the Internet has created the need for security and, more specifically, the need for privacy and authenticity. While encryption is used to achieve privacy, authenticity can be achieved by means of digital signature schemes.
In this talk, I present DHIES, a public-key encryption scheme based on the Diffie-Hellman problem, which deals with the issue of privacy. DHIES is built in a generic way from lower-level primitives: it uses a symmetric encryption scheme, a message authentication code, group operations in an arbitrary group, and a hash function. The scheme is very efficient and has strong security properties. Furthermore, these security properties are proven to hold under appropriate assumptions on the underlying primitives. DHIES is now embodied in two draft standards, IEEE P1363a and ANSI X9.63EC, and the corporate standard SECG.
I will also briefly mention some of my work in other areas of cryptography, including broadcast encryption and forward-secure digital signatures.