4 research outputs found
Side-Channel Leakage through Static Power – Should We Care about in Practice? –
By shrinking the technology static power consumption of CMOS circuits is becoming a major concern. In this paper, we present the first practical results of exploiting static power consumption of FPGA-based cryptographic devices in order to mount a key-recovery side-channel attack. The experiments represented here are based on three Xilinx FPGAs built on 65nm, 45nm, and 28nm process technologies. By means of a sophisticated measurement setup and methodology we demonstrate an exploitable information leakage through static power of the underlying FPGAs. The current work highlights the feasibility of side-channel analysis attacks by static power that have been known for years but have not been performed and investigated in practice yet. This is a starting point for further research investigations, and may have a significant impact on the efficiency of DPA countermeasures in the near future
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
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
EM Side Channel Analysis on Complex SoC architectures
The EM side channel analysis is a very effective technique to attack cryptographic systems due to its non invasive nature and capability to launch an attack even with limited resources. The EM leakage from devices can give information about computations on the processor, which can in turn reveal the internal state of the algorithm. For security sensitive algorithms, these EM radiations can be exploited by the adversary to extract secret key dependent operations hence EM side channel must be studied for evaluating the security of these algorithms. Modern embedded devices composed of System-on-Chip architectures are considered hard targets for EM side channel analysis mainly due to their complex architecture. This thesis explores the viability of EM side channel attacks on such targets. There is a comprehensive literature overview of EM side channel analysis followed by a practical side channel attack on a SoC device using well know cryptographic library OpenSSL. The attack successfully extracts the secret key dependent operation which can be used to retrieve the private key in security protocols such as TLS and SSH. The thesis concludes, with practical single trace attacks, that cryptographic implementations can still be broken using EM side channel analysis, and a complex nature of the device have no significant effect when combined with signal processing methods for extracting side channel information, hence the cryptographic software implementations must address these issues