1,580 research outputs found
Design and evaluation of countermeasures against fault injection attacks and power side-channel leakage exploration for AES block cipher
Differential Fault Analysis (DFA) and Power Analysis (PA) attacks, have become the main
methods for exploiting the vulnerabilities of physical implementations of block ciphers, currently used in
a multitude of applications, such as the Advanced Encryption Standard (AES). In order to minimize these
types of vulnerabilities, several mechanisms have been proposed to detect fault attacks. However, these
mechanisms can have a signi cant cost, not fully covering the implementations against fault attacks or not
taking into account the leakage of the information exploitable by the power analysis attacks. In this paper,
four different approaches are proposed with the aim of protecting the AES block cipher against DFA. The
proposed solutions are based on Hamming code and parity bits as signature generators for the internal state of
the AES cipher. These allow to detect DFA exploitable faults, from bit to byte level. The proposed solutions
have been applied to a T-box based AES block cipher implemented on Field Programmable Gate Array
(FPGA). Experimental results suggest a fault coverage of 98.5% and 99.99% with an area penalty of 9%
and 36% respectively, for the parity bit signature generators and a fault coverage of 100% with an area
penalty of 18% and 42% respectively when Hamming code signature generator is used. In addition, none
of the proposed countermeasures impose a frequency degradation, in respect to the unprotected cipher. The
proposed work goes further in the evaluation of the proposed DFA countermeasures by evaluating the impact
of these structures in terms of power side-channel. The obtained results suggest that no extra information
leakage is produced that can be exploited by PA. Overall, the proposed DFA countermeasures provide a
high fault coverage protection with a low cost in terms of area and power consumption and no PA security
degradation
A Touch of Evil: High-Assurance Cryptographic Hardware from Untrusted Components
The semiconductor industry is fully globalized and integrated circuits (ICs)
are commonly defined, designed and fabricated in different premises across the
world. This reduces production costs, but also exposes ICs to supply chain
attacks, where insiders introduce malicious circuitry into the final products.
Additionally, despite extensive post-fabrication testing, it is not uncommon
for ICs with subtle fabrication errors to make it into production systems.
While many systems may be able to tolerate a few byzantine components, this is
not the case for cryptographic hardware, storing and computing on confidential
data. For this reason, many error and backdoor detection techniques have been
proposed over the years. So far all attempts have been either quickly
circumvented, or come with unrealistically high manufacturing costs and
complexity.
This paper proposes Myst, a practical high-assurance architecture, that uses
commercial off-the-shelf (COTS) hardware, and provides strong security
guarantees, even in the presence of multiple malicious or faulty components.
The key idea is to combine protective-redundancy with modern threshold
cryptographic techniques to build a system tolerant to hardware trojans and
errors. To evaluate our design, we build a Hardware Security Module that
provides the highest level of assurance possible with COTS components.
Specifically, we employ more than a hundred COTS secure crypto-coprocessors,
verified to FIPS140-2 Level 4 tamper-resistance standards, and use them to
realize high-confidentiality random number generation, key derivation, public
key decryption and signing. Our experiments show a reasonable computational
overhead (less than 1% for both Decryption and Signing) and an exponential
increase in backdoor-tolerance as more ICs are added
On Borrowed Time -- Preventing Static Power Side-Channel Analysis
In recent years, static power side-channel analysis attacks have emerged as a
serious threat to cryptographic implementations, overcoming state-of-the-art
countermeasures against side-channel attacks. The continued down-scaling of
semiconductor process technology, which results in an increase of the relative
weight of static power in the total power budget of circuits, will only improve
the viability of static power side-channel analysis attacks. Yet, despite the
threat posed, limited work has been invested into mitigating this class of
attack. In this work we address this gap. We observe that static power
side-channel analysis relies on stopping the target circuit's clock over a
prolonged period, during which the circuit holds secret information in its
registers. We propose Borrowed Time, a countermeasure that hinders an
attacker's ability to leverage such clock control. Borrowed Time detects a
stopped clock and triggers a reset that wipes any registers containing
sensitive intermediates, whose leakages would otherwise be exploitable. We
demonstrate the effectiveness of our countermeasure by performing practical
Correlation Power Analysis attacks under optimal conditions against an AES
implementation on an FPGA target with and without our countermeasure in place.
In the unprotected case, we can recover the entire secret key using traces from
1,500 encryptions. Under the same conditions, the protected implementation
successfully prevents key recovery even with traces from 1,000,000 encryptions
An Outline of Security in Wireless Sensor Networks: Threats, Countermeasures and Implementations
With the expansion of wireless sensor networks (WSNs), the need for securing
the data flow through these networks is increasing. These sensor networks allow
for easy-to-apply and flexible installations which have enabled them to be used
for numerous applications. Due to these properties, they face distinct
information security threats. Security of the data flowing through across
networks provides the researchers with an interesting and intriguing potential
for research. Design of these networks to ensure the protection of data faces
the constraints of limited power and processing resources. We provide the
basics of wireless sensor network security to help the researchers and
engineers in better understanding of this applications field. In this chapter,
we will provide the basics of information security with special emphasis on
WSNs. The chapter will also give an overview of the information security
requirements in these networks. Threats to the security of data in WSNs and
some of their counter measures are also presented
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