Formal analysis of two Buyer-Seller Watermarking Protocols

Abstract

In this paper we demonstrate how the formal model constructed in our previous work [1], can be modified in order to analyse additional Buyer-Seller Watermarking Protocols, identifying which specific sections of the CSP scripts remain identical and which require modification. First, we model the protocol proposed by Memon and Wong [2], an examplar of the Offline Watermarking Authority (OFWA) Model, defined in the framework by Poh and Martin [3]. Second, we model the Shao protocol [4] as an example of a protocol fitting the Online Watermarking Authority (ONWA) Model. Our analysis of the protocols reaffirms the unbinding attack described by Lei et al. [5] on the Memon andWong protocol and we identify a new unbinding attack on the protocol proposed by Shao. © Springer-Verlag Berlin Heidelberg 2009.