Quartz, an asymmetric signature scheme for short signatures on PC Primitive specification and supporting documentation

Note: This document specifies the updated final version of the Quartz signature scheme, slightly modified as allowed in the second stage of Nessie evaluation process, in order to improve the speed and the security. In some papers that refer to the old version, it is sometimes called Quartz, and Quartz is the new version. This is therefore the only official version of Quartz. We note that the key generation has not changed, the signature computation has changed, and the signature verification has changed slightly. In the Appendix of the present document we summarize all the changes to Quartz, for readers and developers that are acquainted with the previous version. It also includes an explanation why these changes has been made.