A number of different buyer-seller watermarking protocols have been proposed to address preserving the rights of both the buyer and the seller. However, these existing schemes are inefficient and impractical for their high computation and bandwidth overhead. To this end, we propose a new buyer-seller watermarking protocol, where the multimedia data is encrypted using a symmetric cipher, and the public-key cipher is only used to key exchanging and data signing. Compared with the existing schemes, our scheme requires a lower computing power and communication bandwidth. In addition, some main drawbacks of those previous schemes are overcome in our scheme.