Program obfuscation is a popular cryptographic construct with a wide range of uses such as IP theft prevention. Although cryptographic solutions for program obfuscation impose impractically high overheads, a recent breakthrough leveraging trusted hardware has shown promise. However, the existing solution is based on special-purpose trusted hardware, restricting its use-cases to a limited few.
In this paper, we first study if such obfuscation is feasible based on commodity trusted hardware, Intel SGX, and we observe that certain important security considerations are not
afforded by commodity hardware. In particular, we found that existing obfuscation/obliviousness schemes are insecure if directly applied to Intel SGX primarily due to side-channel limitations. To this end, we present OBFUSCURO, the first system providing
program obfuscation using commodity trusted hardware, Intel SGX. The key idea is to leverage ORAM operations to perform secure code execution and data access. Initially, OBFUSCURO transforms the regular program layout into a side-channel secure and ORAM-compatible layout. Then, OBFUSCURO ensures that its ORAM controller performs data oblivious accesses in order to protect itself from all memory-based side-channels.
Furthermore, OBFUSCURO ensures that the program is secure from timing attacks by ensuring that the program always runs for a pre-configured time interval. Along the way, OBFUSCURO also introduces a systematic optimization such as register-based ORAM stash. We provide a thorough security analysis of OBFUSCURO along with empirical attack evaluations showing that OBFUSCURO can protect the SGX program execution from
being leaked by access pattern-based and timing-based channels. We also provide a detailed performance benchmark results in order to show the practical aspects of OBFUSCURO.
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Key Update Countermeasure for Correlation-Based Side-Channel Attacks
Side-channel analysis is a non-invasive form of attack that reveals the secret key of the cryptographic circuit by analyzing the leaked physical information. The traditional brute-force and cryptanalysis attacks target the weakness in the encryption algorithm, whereas side-channel attacks use statistical models such as differential analysis and correlation analysis on the leaked information gained from the cryptographic device during the run-time. As a non-invasive and passive attack, the side-channel attack brings a lot of difficulties for detection and defense. In this work, we propose a key update scheme
as a countermeasure for power and electromagnetic analysis-based attacks on the cryptographic device. The proposed countermeasure utilizes a secure coprocessor to provide secure key generation and storage in a trusted environment. The experimental results show that the proposed key update scheme can mitigate side-channel attacks significantly.
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- Award ID(s):
- 1814420
- NSF-PAR ID:
- 10169992
- Date Published:
- Journal Name:
- Journal of hardware and systems security
- ISSN:
- 2509-3436
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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