2016-06-23 11.00 am s.t.
Dennis Hofheinz Karlsruhe Institute of Technology
CISPA 0.05

Cryptographic building blocks

Dennis Hofheinz

Karlsruhe Institute of Technology

Title : Cryptographic building blocks

Building: E9 1 (CISPA), Room 0.05, Lecture hall


Cryptography provides a toolbox of universal technical building blocks that
are crucial ingredients in the construction of secure systems. Some of these
building blocks (such as encryption schemes) have a long history, and have
been subject to extensive research. Other building blocks (such as
obfuscation) have only recently been introduced, and enable completely new
applications. This talk gives a survey, and a subjective view on current and
future challenges in cryptography. Specifically, we showcase recent
developments in traditional and new building blocks.

In the area of traditional building blocks, we highlight the concept of “tight
security reductions”. A tight security reduction provides security guarantees
that do not depend on the size of the setting in which the building block is
deployed. Such building blocks are particularly suitable for “Big Data”
settings with a priori unknown size. We explain the difficulties in achieving
tight security reductions, and give an overview over the current state of the

We also survey new cryptographic building blocks, such as obfuscation, fully
homomorphic encryption, and multilinear maps. All of these building blocks
have been introduced recently, enable previously unachievable applications,
and are currently far too immature (and in particular far too inefficient) for
deployment. We believe that the key to approaching modern applications (which
usually cannot be handled with traditional cryptographic building blocks
alone) is the refinement of these new cryptographic building blocks. We give
example applications, showcase first results, and provide an outlook into the
future of such new building blocks.