2,035 research outputs found
Secret Key Leakage from Public Key Perturbation of DLP-based Cryptosystems
Finding efficient countermeasures for cryptosystems against fault attacks is challenged by a constant discovery of flaws in designs. Even elements, such as public keys, that do not seem critical must be protected. From the attacks against RSA, we develop a new attack of DLP-based cryptosystems, built in addition on a lattice analysis to recover DSA public keys from partially known nonces. Based on a realistic fault model, our attack only requires 16 faulty signatures to recover a 160-bit DSA secret key within a few minutes on a standard PC. These results significantly improves the previous public element fault attack in the context of DLP-based cryptosystems
Loop-Abort Faults on Lattice-Based FiatâShamir and Hash-and-Sign Signatures
As the advent of general-purpose quantum computers appears to be drawing closer, agencies and advisory bodies have started recommending that we prepare the transition away from factoring and discrete logarithm-based cryptography, and towards postquantum secure constructions, such as lattice- based schemes.
Almost all primitives of classical cryptography (and more!) can be realized with lattices, and the efficiency of primitives like encryption and signatures has gradually improved to the point that key sizes are competitive with RSA at similar security levels, and fast performance can be achieved both in soft- ware and hardware. However, little research has been conducted on physical attacks targeting concrete implementations of postquantum cryptography in general and lattice-based schemes in particular, and such research is essential if lattices are going to replace RSA and elliptic curves in our devices and smart cards.
In this paper, we look in particular at fault attacks against implementations of lattice-based signature schemes, looking both at FiatâShamir type constructions (particularly BLISS, but also GLP, PASSSing and Ring-TESLA) and at hash-and-sign schemes (particularly the GPV-based scheme of DucasâPrestâ Lyubashevsky). These schemes include essentially all practical lattice-based signatures, and achieve the best efficiency to date in both software and hardware. We present several fault attacks against those schemes yielding a full key recovery with only a few or even a single faulty signature, and discuss possible countermeasures to protect against these attacks
Quantum attacks on Bitcoin, and how to protect against them
The key cryptographic protocols used to secure the internet and financial
transactions of today are all susceptible to attack by the development of a
sufficiently large quantum computer. One particular area at risk are
cryptocurrencies, a market currently worth over 150 billion USD. We investigate
the risk of Bitcoin, and other cryptocurrencies, to attacks by quantum
computers. We find that the proof-of-work used by Bitcoin is relatively
resistant to substantial speedup by quantum computers in the next 10 years,
mainly because specialized ASIC miners are extremely fast compared to the
estimated clock speed of near-term quantum computers. On the other hand, the
elliptic curve signature scheme used by Bitcoin is much more at risk, and could
be completely broken by a quantum computer as early as 2027, by the most
optimistic estimates. We analyze an alternative proof-of-work called Momentum,
based on finding collisions in a hash function, that is even more resistant to
speedup by a quantum computer. We also review the available post-quantum
signature schemes to see which one would best meet the security and efficiency
requirements of blockchain applications.Comment: 21 pages, 6 figures. For a rough update on the progress of Quantum
devices and prognostications on time from now to break Digital signatures,
see https://www.quantumcryptopocalypse.com/quantum-moores-law
Algorithmic Security is Insufficient: A Comprehensive Survey on Implementation Attacks Haunting Post-Quantum Security
This survey is on forward-looking, emerging security concerns in post-quantum
era, i.e., the implementation attacks for 2022 winners of NIST post-quantum
cryptography (PQC) competition and thus the visions, insights, and discussions
can be used as a step forward towards scrutinizing the new standards for
applications ranging from Metaverse, Web 3.0 to deeply-embedded systems. The
rapid advances in quantum computing have brought immense opportunities for
scientific discovery and technological progress; however, it poses a major risk
to today's security since advanced quantum computers are believed to break all
traditional public-key cryptographic algorithms. This has led to active
research on PQC algorithms that are believed to be secure against classical and
powerful quantum computers. However, algorithmic security is unfortunately
insufficient, and many cryptographic algorithms are vulnerable to side-channel
attacks (SCA), where an attacker passively or actively gets side-channel data
to compromise the security properties that are assumed to be safe
theoretically. In this survey, we explore such imminent threats and their
countermeasures with respect to PQC. We provide the respective, latest
advancements in PQC research, as well as assessments and providing visions on
the different types of SCAs
Envisioning the Future of Cyber Security in Post-Quantum Era: A Survey on PQ Standardization, Applications, Challenges and Opportunities
The rise of quantum computers exposes vulnerabilities in current public key
cryptographic protocols, necessitating the development of secure post-quantum
(PQ) schemes. Hence, we conduct a comprehensive study on various PQ approaches,
covering the constructional design, structural vulnerabilities, and offer
security assessments, implementation evaluations, and a particular focus on
side-channel attacks. We analyze global standardization processes, evaluate
their metrics in relation to real-world applications, and primarily focus on
standardized PQ schemes, selected additional signature competition candidates,
and PQ-secure cutting-edge schemes beyond standardization. Finally, we present
visions and potential future directions for a seamless transition to the PQ
era
Analysis and Mitigation of Remote Side-Channel and Fault Attacks on the Electrical Level
In der fortlaufenden Miniaturisierung von integrierten Schaltungen werden physikalische Grenzen erreicht, wobei beispielsweise Einzelatomtransistoren eine mögliche untere Grenze fĂŒr StrukturgröĂen darstellen.
Zudem ist die Herstellung der neuesten Generationen von Mikrochips heutzutage finanziell nur noch von groĂen, multinationalen Unternehmen zu stemmen.
Aufgrund dieser Entwicklung ist Miniaturisierung nicht lÀnger die treibende Kraft um die Leistung von elektronischen Komponenten weiter zu erhöhen.
Stattdessen werden klassische Computerarchitekturen mit generischen Prozessoren weiterentwickelt zu heterogenen Systemen mit hoher ParallelitÀt und speziellen Beschleunigern.
Allerdings wird in diesen heterogenen Systemen auch der Schutz von privaten Daten gegen Angreifer zunehmend schwieriger.
Neue Arten von Hardware-Komponenten, neue Arten von Anwendungen und eine allgemein erhöhte KomplexitÀt sind einige der Faktoren, die die Sicherheit in solchen Systemen zur Herausforderung machen.
Kryptografische Algorithmen sind oftmals nur unter bestimmten Annahmen ĂŒber den Angreifer wirklich sicher.
Es wird zum Beispiel oft angenommen, dass der Angreifer nur auf Eingaben und Ausgaben eines Moduls zugreifen kann, wÀhrend interne Signale und Zwischenwerte verborgen sind.
In echten Implementierungen zeigen jedoch Angriffe ĂŒber SeitenkanĂ€le und Faults die Grenzen dieses sogenannten Black-Box-Modells auf.
WĂ€hrend bei Seitenkanalangriffen der Angreifer datenabhĂ€ngige MessgröĂen wie Stromverbrauch oder elektromagnetische Strahlung ausnutzt, wird bei Fault Angriffen aktiv in die Berechnungen eingegriffen, und die falschen Ausgabewerte zum Finden der geheimen Daten verwendet.
Diese Art von Angriffen auf Implementierungen wurde ursprĂŒnglich nur im Kontext eines lokalen Angreifers mit Zugriff auf das ZielgerĂ€t behandelt.
Jedoch haben bereits Angriffe, die auf der Messung der Zeit fĂŒr bestimmte Speicherzugriffe basieren, gezeigt, dass die Bedrohung auch durch Angreifer mit Fernzugriff besteht.
In dieser Arbeit wird die Bedrohung durch Seitenkanal- und Fault-Angriffe ĂŒber Fernzugriff behandelt, welche eng mit der Entwicklung zu mehr heterogenen Systemen verknĂŒpft sind.
Ein Beispiel fĂŒr neuartige Hardware im heterogenen Rechnen sind Field-Programmable Gate Arrays (FPGAs), mit welchen sich fast beliebige Schaltungen in programmierbarer Logik realisieren lassen.
Diese Logik-Chips werden bereits jetzt als Beschleuniger sowohl in der Cloud als auch in EndgerÀten eingesetzt.
Allerdings wurde gezeigt, wie die FlexibilitÀt dieser Beschleuniger zur Implementierung von Sensoren zur AbschÀtzung der Versorgungsspannung ausgenutzt werden kann.
Zudem können durch eine spezielle Art der Aktivierung von groĂen Mengen an Logik Berechnungen in anderen Schaltungen fĂŒr Fault Angriffe gestört werden.
Diese Bedrohung wird hier beispielsweise durch die Erweiterung bestehender Angriffe weiter analysiert und es werden Strategien zur Absicherung dagegen entwickelt
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