Re: PHD subject

From: Stephen Riley (
Date: 10/07/05

Date: Fri, 7 Oct 2005 12:16:06 +0100

In message <>,
Student <> writes

>I m looking for PHD subject in number theory. it may be deal with
>factorization. can you help me?

How about something related to Identity Based Encryption? A new and
possibly very important field in the future, and one where security was
once, and perhaps still is, an open question. A lot of work seems to
have been done in recent times that (appear to) claim some schemes are
provably secure, but with conclusions too obscure or mathematically
involved for me to figure out satisfactorily without a heck of a longer

E.g. Identity-Based
Encryption from the Weil Pairing (2003)

"...The BDH assumption deserves further study considering the powerful
cryptosystems derived from it..."

"...It is an open problem to build chosen ciphertext secure identity
based systems that are secure in the standard computation model..."

"...We refer to this assumption as BDDH..."

"...Building a chosen ciphertext secure IBE (IND-ID-CCA) in the standard
model is currently an open problem..."

Links to other research here

Stephen Riley