A secure and privacy protection digital goods trading scheme in cloud computing

In a cloud computing environment, a seller can store her/his digital goods in a cloud server, and then sell them when a buyer needs. In order to protect the digital content´s privacy, the seller should store her/his digital goods in an encrypted form before being stored in a cloud. However, the method of directly encrypting digital goods maybe not work well if buyers and sellers trade with the digital goods in this environment. The reason is that the cloud server could not decide which digital goods contain certain keywords requested by a buyer if the meta data of the encrypted digital goods is not searchable. In this paper, we propose a secure digital goods trading scheme in the cloud computing. Our scheme can efficiently protect keywords privacy for buyers, and make the cloud server to search the keywords on the encrypted digital content to protect the privacy of sellers´ digital content. We also provide an efficient trading method to let buyers and sellers trade with the matched digital goods in a cloud.