Controlled Copying of Persistent Data Between end Users' SGX Enclaves over an Untrusted Network

It is difficult to protect digital rights while allowing data to be freely copied over the Internet. This paper describes controlled copying of persistent data between two end users's PCs without centralized servers. In the proposed method, a user accesses protected data through the program running in a trusted execution environment (TEE) of the user's PC. When a user sends data to another user, the program in the sender's TEE first encrypts the data and sends it to the program in the receiver's TEE without access permission. Next, the sender's and receiver's programs perform a distributed transaction, and the sender may pass on some of its access rights to the receiver. For example, in the case of data moving, the sender loses access completely and the receiver gains access. In the case of data leasing, the receiver gains access until the end of the lease period, after which the sender is able to access the data again. The proposed method works on an untrusted network, untrusted local persistent storage, and trusted local monotonic counters. Unlike typical digital rights management (DRM) mechanisms, the proposed method enables the resell of data among users while avoiding censorship or privacy violations. The proposed method has been implemented using Intel Software Guard Extensions (SGX). The proposed method can defend against attacks on programs, storage, and networks. Experimental results show that data moving over the Internet could be performed in a useful time.