  Intel SGX provisions shielded executions for security-sensitive computation,
but lacks support for trusted system services (TSS), such as clock, network and
filesystem. This makes \textit{enclaves} vulnerable to Iago
attacks~\cite{DBLP:conf/asplos/CheckowayS13} in the face of a powerful
malicious system. To mitigate this problem, we present Aurora, a novel
architecture that provides TSSes via a secure channel between enclaves and
devices on top of an untrusted system, and implement two types of TSSes, i.e.
clock and end-to-end network. We evaluate our solution by porting SQLite and
OpenSSL into Aurora, experimental results show that SQLite benefits from a
\textit{microsecond} accuracy trusted clock and OpenSSL gains end-to-end secure
network with about 1ms overhead.
