Data privacy is an important issue for businesses, governments, and the general public. Blockchain is an emerging technology that decentralizes trust among a number of potentially malicious peers in comparison to centralized systems. One of the challenges for blockchain systems is to provide privacy while providing high transaction throughput. Intel Software Guard Extensions (SGX), and other Trusted Execution Environments (TEEs) provide trust guarantees when executing a piece of code. Through this technology, several aspects of blockchains can be anonymized, thus preserving data privacy . In this paper, we present a systematic literature review of blockchain systems that use data privacy techniques with a focus on applications of Intel SGX.