562 research outputs found
Formal Analysis of CRT-RSA Vigilant's Countermeasure Against the BellCoRe Attack: A Pledge for Formal Methods in the Field of Implementation Security
In our paper at PROOFS 2013, we formally studied a few known countermeasures
to protect CRT-RSA against the BellCoRe fault injection attack. However, we
left Vigilant's countermeasure and its alleged repaired version by Coron et al.
as future work, because the arithmetical framework of our tool was not
sufficiently powerful. In this paper we bridge this gap and then use the same
methodology to formally study both versions of the countermeasure. We obtain
surprising results, which we believe demonstrate the importance of formal
analysis in the field of implementation security. Indeed, the original version
of Vigilant's countermeasure is actually broken, but not as much as Coron et
al. thought it was. As a consequence, the repaired version they proposed can be
simplified. It can actually be simplified even further as two of the nine
modular verifications happen to be unnecessary. Fortunately, we could formally
prove the simplified repaired version to be resistant to the BellCoRe attack,
which was considered a "challenging issue" by the authors of the countermeasure
themselves.Comment: arXiv admin note: substantial text overlap with arXiv:1401.817
An Enhanced Dataflow Analysis to Automatically Tailor Side Channel Attack Countermeasures to Software Block Ciphers
Protecting software implementations of block ciphers from side channel attacks is a significant concern to realize secure embedded computation platforms. The relevance of the issue calls for the automation of the side channel vulnerability assessment of a block cipher implementation, and the automated application of provably secure defenses. The most recent methodology in the field is an application of a specialized data-flow analysis, performed by means of the LLVM compiler framework, detecting in the AES cipher the portions of the code
amenable to key extraction via side channel analysis. The contribution of this work is an enhancement to the existing data-flow analysis which extending it to tackle any block cipher implemented in software. In particular, the extended strategy takes fully into account the data dependencies present in the key schedule of a block cipher, regardless of its complexity, to obtain consistently sound results. This paper details the analysis strategy and presents new results on the tailored application of power and electro-magnetic emission analysis countermeasures, evaluating the performances on both the ARM Cortex-M and the MIPS ISA. The experimental evaluation reports a case study on two block ciphers: the first designed to achieve a high security margin at a non-negligible computational cost, and a lightweight one. The results show that, when side-channel-protected implementations are considered, the high-security block cipher is indeed more efficient than the lightweight one
Circuit-Variant Moving Target Defense for Side-Channel Attacks on Reconfigurable Hardware
With the emergence of side-channel analysis (SCA) attacks, bits of a secret key may be derived by correlating key values with physical properties of cryptographic process execution. Power and Electromagnetic (EM) analysis attacks are based on the principle that current flow within a cryptographic device is key-dependent and therefore, the resulting power consumption and EM emanations during encryption and/or decryption can be correlated to secret key values. These side-channel attacks require several measurements of the target process in order to amplify the signal of interest, filter out noise, and derive the secret key through statistical analysis methods. Differential power and EM analysis attacks rely on correlating actual side-channel measurements to hypothetical models. This research proposes increasing resistance to differential power and EM analysis attacks through structural and spatial randomization of an implementation. By introducing randomly located circuit variants of encryption components, the proposed moving target defense aims to disrupt side-channel collection and correlation needed to successfully implement an attac
Power Side Channels in Security ICs: Hardware Countermeasures
Power side-channel attacks are a very effective cryptanalysis technique that
can infer secret keys of security ICs by monitoring the power consumption.
Since the emergence of practical attacks in the late 90s, they have been a
major threat to many cryptographic-equipped devices including smart cards,
encrypted FPGA designs, and mobile phones. Designers and manufacturers of
cryptographic devices have in response developed various countermeasures for
protection. Attacking methods have also evolved to counteract resistant
implementations. This paper reviews foundational power analysis attack
techniques and examines a variety of hardware design mitigations. The aim is to
highlight exposed vulnerabilities in hardware-based countermeasures for future
more secure implementations
SNIFF: Reverse Engineering of Neural Networks with Fault Attacks
Neural networks have been shown to be vulnerable against fault injection
attacks. These attacks change the physical behavior of the device during the
computation, resulting in a change of value that is currently being computed.
They can be realized by various fault injection techniques, ranging from
clock/voltage glitching to application of lasers to rowhammer. In this paper we
explore the possibility to reverse engineer neural networks with the usage of
fault attacks. SNIFF stands for sign bit flip fault, which enables the reverse
engineering by changing the sign of intermediate values. We develop the first
exact extraction method on deep-layer feature extractor networks that provably
allows the recovery of the model parameters. Our experiments with Keras library
show that the precision error for the parameter recovery for the tested
networks is less than with the usage of 64-bit floats, which
improves the current state of the art by 6 orders of magnitude. Additionally,
we discuss the protection techniques against fault injection attacks that can
be applied to enhance the fault resistance
Encasing Block Ciphers to Foil Key Recovery Attempts via Side Channel
Providing efficient protection against energy consumption based side channel attacks (SCAs) for block ciphers is a relevant topic for the research community, as current overheads are in the 100×
range. Unprofiled SCAs exploit information leakage from the outmost rounds of a cipher; we propose a solution encasing it between keyed transformations amenable to an efficient SCA protection. Our solution can be employed as a drop in replacement for an unprotected implementation, or be retrofit to an existing one, while retaining communication capabilities with legacy insecure endpoints. Experiments on a Cortex-M4 μC, show performance improvements
in the range of 60×, compared with available solutions
- …