A study on the data privacy and operation performance for cloud collaborative editing systems

This paper deals with the problem of collaboratively secure document editing in cloud environment. Using cloud document editing service, several users can create and edit a document collaboratively. However, as the cloud service provider is not trusted to guarantee the confidentiality of these documents, existing methods encrypt the documents before uploading them to the cloud. While these approaches can be inefficient for collaborative editing, we propose to organize the content of a document using a Red-Black tree and encrypt each block of data separately, so as to improve the performance of collaborative editing systems. Although creating and maintaining the Red-Black tree introduces extra cost, compared to the whole document encryption strategy the experimental results show that for text editing operations, such as insertion and removal, the use of Red-Black tree algorithm improves efficiency by 31.04% if 3DES encryption is applied and by 23.94% if applying AES encryption.