Vortrag
Lattice-based cryptography: an introduction
Vortrag von Cecilia Boschini
Datum: 08.11.17 Zeit: 15.00 - 16.00 Raum: Y27H12
Lattice-based cryptography is defined by Peikert as the use of
conjectured hard problems over point lattices in R^n as the foundation
to build cryptographic schemes. In the last 20 years, it has emerged
along with code-based and multivariate cryptography as one of the main
candidate quantum-secure cryptosystem. Indeed, in addition to the
supposed resistance against quantum attacks, lattice problems guarantee
security under worst-case hardness assumptions and working over lattices
allows to build a wide range of schemes that were hard to construct
under factoring or DDH assumptions, like fully homomorphic encryption.
Moreover, algorithms built over lattices are asymptotically efficient
and highly parallelizable.
In this introductory talk, we aim to give the audience the intuition
behind lattice-based cryptography to lay the necessary foundations for
further in-depth analysis. After introducing lattices as a mathematical
concept, we will focus on how to build preimage sampleable functions,
i.e. functions that are easy to compute and hard to invert without
knowledge of a trapdoor. Preimage sampleable functions are a fundamental
cryptographic primitive, as they can be used to build digital signatures
and identity-based encryption.