Publikationen

Autor	Brasser, Ferdinand; Capkun, Srdjan; Dmitrienko, Alexandra; Frassetto, Tommaso; Kostiainen, Kari; Müller, Urs; Sadeghi, Ahmad-Reza
Datum	2017
Art	Report
Abstrakt	Recent research has demonstrated that Intel's SGX is vulnerable to various software-based side-channel attacks. In particular, attacks that monitor CPU caches shared between the victim enclave and untrusted software enable accurate leakage of secret enclave data. Known defenses assume developer assistance, require hardware changes, impose high overhead, or prevent only some of the known attacks. In this paper we propose data location randomization as a novel defensive approach to address the threat of side-channel attacks. Our main goal is to break the link between the cache observations by the privileged adversary and the actual data accesses by the victim. We design and implement a compiler-based tool called DR.SGX that instruments enclave code such that data locations are permuted at the granularity of cache lines. We realize the permutation with the CPU's cryptographic hardware-acceleration units providing secure randomization. To prevent correlation of repeated memory accesses we continuously re-randomize all enclave data during execution. Our solution effectively protects many (but not all) enclaves from cache attacks and provides a complementary enclave hardening technique that is especially useful against unpredictable information leakage.
Schlüssel	TUD-CS-2017-0255
Url	https://tubiblio.ulb.tu-darmstadt.de/id/eprint/97778