pleased to announce that the next QuEnG Quantum Computing seminar will be given by Cécilia Lancien (Institut Fourier, Grenoble) on Wednesday 13 October at 2pm at LIG (room 406, IMAG building), as well as on Zoom as a hybrid event (link below) for those unable to attend in person. 

Title: Weak approximate unitary designs and applications to quantum encryption

Abstract: Unitary t-designs are central objects in many areas of quantum information theory. An important issue in practice is that of efficiently constructing good approximations of such unitary t-designs. It turns out that sampling only order d^t*poly(t,log(d)) unitaries from a t-design provides with positive probability an approximate t-design. And this result can actually be shown to be optimal (up to log(d) factors). I will try to explain all of this in detail. As an application, I will present a randomized construction of a quantum encryption scheme which has a large amount of key, while having indistinguishable ciphertexts and being non-malleable, against adversaries with limited side information.

This is based on joint work with Christian Majenz, available at: https://arxiv.org/abs/1911.06742

The seminar will take place in room at LIG, in room 406 of the IMAG building on the campus. Someone will wait in the entrance to provide participants with access to the 4th floor. 

Meeting ID: 985 1551 2137

Passcode: 436965