3,892 research outputs found
Enhancing an Embedded Processor Core with a Cryptographic Unit for Performance and Security
We present a set of low-cost architectural enhancements to accelerate the execution of certain arithmetic operations common in cryptographic applications on an extensible embedded processor core. The proposed enhancements are generic in the sense that they can be beneficially applied in almost any RISC processor. We implemented the enhancements in form of a cryptographic unit (CU) that offers the programmer an extended instruction set. The CU features a 128-bit wide register file and datapath, which enables it to process 128-bit words and perform 128-bit loads/stores. We analyze the speed-up factors for some arithmetic operations and public-key cryptographic algorithms obtained through
these enhancements. In addition, we evaluate the hardware overhead (i.e. silicon area) of integrating the CU into an embedded RISC processor. Our experimental results show that the proposed architectural enhancements allow for a
significant performance gain for both RSA and ECC at the expense of an acceptable increase in silicon area. We also demonstrate that the proposed enhancements facilitate the protection of cryptographic algorithms against certain types of side-channel attacks and present an AES implementation
hardened against cache-based attacks as a case study
Design and implementation of robust embedded processor for cryptographic applications
Practical implementations of cryptographic algorithms are vulnerable to side-channel analysis and fault attacks. Thus, some masking and fault detection algorithms must be incorporated into these implementations. These additions further increase the complexity of the cryptographic devices which already need to perform computationally-intensive operations. Therefore, the general-purpose processors are usually supported by coprocessors/hardware accelerators to protect as well as to accelerate cryptographic applications. Using a configurable processor is just another solution. This work designs and implements robust execution units as an extension to a configurable processor, which detect the data faults (adversarial or otherwise) while performing the arithmetic operations. Assuming a capable adversary who can injects faults to the cryptographic computation with high precision, a nonlinear error detection code with high error detection capability is used. The designed units are tightly integrated to the datapath of the configurable processor using its tool chain. For different configurations, we report the increase in the space and time complexities of the configurable processor. Also, we present performance evaluations of the software implementations using the robust execution units. Implementation results show that it is feasible to implement robust arithmetic units with relatively low overhead in an embedded processor
Implementing a protected zone in a reconfigurable processor for isolated execution of cryptographic algorithms
We design and realize a protected zone inside a reconfigurable and extensible embedded RISC processor for isolated execution of cryptographic algorithms. The protected zone is a collection of processor subsystems such as functional units optimized for high-speed execution of integer operations, a small amount of local memory, and general and special-purpose registers. We outline the principles for secure software implementation of cryptographic algorithms
in a processor equipped with the protected zone. We also demonstrate the efficiency and effectiveness of the protected zone by implementing major cryptographic algorithms, namely RSA, elliptic curve cryptography, and AES in the protected zone. In terms of time efficiency, software implementations
of these three cryptographic algorithms outperform equivalent software implementations on similar processors reported in the literature. The protected zone is designed in such a modular fashion that it can easily be integrated into any RISC processor; its area overhead is considerably moderate in the sense that
it can be used in vast majority of embedded processors. The protected zone can also provide the necessary support to implement TPM functionality within the boundary of a processor
Software Grand Exposure: SGX Cache Attacks Are Practical
Side-channel information leakage is a known limitation of SGX. Researchers
have demonstrated that secret-dependent information can be extracted from
enclave execution through page-fault access patterns. Consequently, various
recent research efforts are actively seeking countermeasures to SGX
side-channel attacks. It is widely assumed that SGX may be vulnerable to other
side channels, such as cache access pattern monitoring, as well. However, prior
to our work, the practicality and the extent of such information leakage was
not studied.
In this paper we demonstrate that cache-based attacks are indeed a serious
threat to the confidentiality of SGX-protected programs. Our goal was to design
an attack that is hard to mitigate using known defenses, and therefore we mount
our attack without interrupting enclave execution. This approach has major
technical challenges, since the existing cache monitoring techniques experience
significant noise if the victim process is not interrupted. We designed and
implemented novel attack techniques to reduce this noise by leveraging the
capabilities of the privileged adversary. Our attacks are able to recover
confidential information from SGX enclaves, which we illustrate in two example
cases: extraction of an entire RSA-2048 key during RSA decryption, and
detection of specific human genome sequences during genomic indexing. We show
that our attacks are more effective than previous cache attacks and harder to
mitigate than previous SGX side-channel attacks
On Making Emerging Trusted Execution Environments Accessible to Developers
New types of Trusted Execution Environment (TEE) architectures like TrustLite
and Intel Software Guard Extensions (SGX) are emerging. They bring new features
that can lead to innovative security and privacy solutions. But each new TEE
environment comes with its own set of interfaces and programming paradigms,
thus raising the barrier for entry for developers who want to make use of these
TEEs. In this paper, we motivate the need for realizing standard TEE interfaces
on such emerging TEE architectures and show that this exercise is not
straightforward. We report on our on-going work in mapping GlobalPlatform
standard interfaces to TrustLite and SGX.Comment: Author's version of article to appear in 8th Internation Conference
of Trust & Trustworthy Computing, TRUST 2015, Heraklion, Crete, Greece,
August 24-26, 201
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