Abstract
We investigate the quantum signature scheme proposed by and Zeng and Keitel [Phys. Rev. A 65, 042312 (2002)]. It uses Greenberger-Horne-Zeilinger states and the availability of a trusted arbitrator. However, in our opinion the protocol is not clearly operationally defined and several steps are ambiguous. Moreover, we argue that the security statements claimed by the authors are incorrect.
- Received 16 August 2007
DOI:https://doi.org/10.1103/PhysRevA.77.046301
©2008 American Physical Society
