# QIS

## Seminar

### 1. A new protocol for high bit rates 2. A new type of security proofs

Seminar Room 2, Newton Institute Gatehouse

#### Abstract

Main message: Q crypto is entering the industrial age, but basic research is still needed. Examples: 1. New Q crypto protocols should be designed taking into account realistic constraints. Examples are "continuous variables" and the SARG protocol [PRL 92,057901,2004]. In this talk we present another new protocol that aims at Gbit/sec rates.

2. It is desirable to simplify proofs of security against the most general coherent attack. We take advantage of some recent results in classical information based cryptography and on the symmetry of the 6-state protocol to demonstrate that coherent attacks are not more powerfull than collective attacks. Using this we present a new kind of security proof that improves over the Shor-Preskill result.