17,135 research outputs found
Guessing Less and Better: Improved Attacks on GIFT-64
GIFT-64 is a block cipher that has received a lot of attention from the community since its proposal in 2017. The attack on the highest number of rounds is a differential related-key attack on 26 rounds~\cite{DBLP:journals/tosc/SunWW21}. We studied this attack, in particular with respect to the generic framework for improving key recovery from~\cite{DBLP:conf/asiacrypt/BrollCFLN21}, and we realised that this framework, combined with an efficient parallel key guessing of interesting subsets of the key and a consequent list merging applied to the partial solutions, can improve the complexity of the attack. We propose two different trade-offs, as a result of the improved key-recovery. We believe that the techniques are quite generic and that it is possible to apply them to improve other differential attacks
Boomerang Connectivity Table:A New Cryptanalysis Tool
A boomerang attack is a cryptanalysis framework that regards a block cipher as the composition of two sub-ciphers and builds a particular characteristic for with probability by combining differential characteristics for and with probability and , respectively.
Crucially the validity of this figure is under the assumption that the characteristics for and can be chosen independently. Indeed, Murphy has shown that independently chosen characteristics may turn out to be incompatible. On the other hand, several researchers observed that the probability can be improved to or around the boundary between and by considering a positive dependency of the two characteristics, e.g.~the ladder switch and S-box switch by Biryukov and Khovratovich.
This phenomenon was later formalised by Dunkelman et al.~as a sandwich attack that regards as , where satisfies some differential propagation among four texts with probability , and the entire probability is .
In this paper, we revisit the issue of dependency of two characteristics in , and propose a new tool called Boomerang Connectivity Table (BCT), which evaluates in a systematic and easy-to-understand way when is composed of a single S-box layer. With the BCT, previous observations on the S-box including the incompatibility, the ladder switch and the S-box switch are represented in a unified manner. Moreover, the BCT can detect a new switching effect, which shows that the probability around the boundary may be even higher than or .
To illustrate the power of the BCT-based analysis, we improve boomerang attacks against Deoxys-BC, and disclose the mechanism behind an unsolved probability amplification for generating a quartet in SKINNY. Lastly, we discuss the issue of searching for S-boxes having good BCT and extending the analysis to modular addition
Routes for breaching and protecting genetic privacy
We are entering the era of ubiquitous genetic information for research,
clinical care, and personal curiosity. Sharing these datasets is vital for
rapid progress in understanding the genetic basis of human diseases. However,
one growing concern is the ability to protect the genetic privacy of the data
originators. Here, we technically map threats to genetic privacy and discuss
potential mitigation strategies for privacy-preserving dissemination of genetic
data.Comment: Draft for comment
Systematizing Genome Privacy Research: A Privacy-Enhancing Technologies Perspective
Rapid advances in human genomics are enabling researchers to gain a better
understanding of the role of the genome in our health and well-being,
stimulating hope for more effective and cost efficient healthcare. However,
this also prompts a number of security and privacy concerns stemming from the
distinctive characteristics of genomic data. To address them, a new research
community has emerged and produced a large number of publications and
initiatives.
In this paper, we rely on a structured methodology to contextualize and
provide a critical analysis of the current knowledge on privacy-enhancing
technologies used for testing, storing, and sharing genomic data, using a
representative sample of the work published in the past decade. We identify and
discuss limitations, technical challenges, and issues faced by the community,
focusing in particular on those that are inherently tied to the nature of the
problem and are harder for the community alone to address. Finally, we report
on the importance and difficulty of the identified challenges based on an
online survey of genome data privacy expertsComment: To appear in the Proceedings on Privacy Enhancing Technologies
(PoPETs), Vol. 2019, Issue
Residual Vulnerabilities to Power side channel attacks of lightweight ciphers cryptography competition Finalists
The protection of communications between Internet of Things (IoT) devices is of great concern because the information exchanged contains vital sensitive data. Malicious agents seek to exploit those data to extract secret information about the owners or the system. Power side channel attacks are of great concern on these devices because their power consumption unintentionally leaks information correlatable to the device\u27s secret data. Several studies have demonstrated the effectiveness of authenticated encryption with advanced data, in protecting communications with these devices. A comprehensive evaluation of the seven (out of 10) algorithm finalists of the National Institute of Standards and Technology (NIST) IoT lightweight cipher competition that do not integrate builtâin countermeasures is proposed. The study shows that, nonetheless, they still present some residual vulnerabilities to power side channel attacks (SCA). For five ciphers, an attack methodology as well as the leakage function needed to perform correlation power analysis (CPA) is proposed. The authors assert that Ascon, Sparkle, and PHOTONâBeetle security vulnerability can generally be assessed with the security assumptions âChosen ciphertext attack and leakage in encryption only, with nonceâmisuse resilience adversary (CCAmL1)â and âChosen ciphertext attack and leakage in encryption only with nonceârespecting adversary (CCAL1)â, respectively. However, the security vulnerability of GIFTâCOFB, Grain, Romulus, and TinyJambu can be evaluated more straightforwardly with publicly available leakage models and solvers. They can also be assessed simply by increasing the number of traces collected to launch the attack
A Comprehensive Survey on the Implementations, Attacks, and Countermeasures of the Current NIST Lightweight Cryptography Standard
This survey is the first work on the current standard for lightweight
cryptography, standardized in 2023. Lightweight cryptography plays a vital role
in securing resource-constrained embedded systems such as deeply-embedded
systems (implantable and wearable medical devices, smart fabrics, smart homes,
and the like), radio frequency identification (RFID) tags, sensor networks, and
privacy-constrained usage models. National Institute of Standards and
Technology (NIST) initiated a standardization process for lightweight
cryptography and after a relatively-long multi-year effort, eventually, in Feb.
2023, the competition ended with ASCON as the winner. This lightweight
cryptographic standard will be used in deeply-embedded architectures to provide
security through confidentiality and integrity/authentication (the dual of the
legacy AES-GCM block cipher which is the NIST standard for symmetric key
cryptography). ASCON's lightweight design utilizes a 320-bit permutation which
is bit-sliced into five 64-bit register words, providing 128-bit level
security. This work summarizes the different implementations of ASCON on
field-programmable gate array (FPGA) and ASIC hardware platforms on the basis
of area, power, throughput, energy, and efficiency overheads. The presented
work also reviews various differential and side-channel analysis attacks (SCAs)
performed across variants of ASCON cipher suite in terms of algebraic,
cube/cube-like, forgery, fault injection, and power analysis attacks as well as
the countermeasures for these attacks. We also provide our insights and visions
throughout this survey to provide new future directions in different domains.
This survey is the first one in its kind and a step forward towards
scrutinizing the advantages and future directions of the NIST lightweight
cryptography standard introduced in 2023
Security analysis of NIST-LWC contest finalists
Dissertação de mestrado integrado em Informatics EngineeringTraditional cryptographic standards are designed with a desktop and server environment in mind, so, with the
relatively recent proliferation of small, resource constrained devices in the Internet of Things, sensor networks,
embedded systems, and more, there has been a call for lightweight cryptographic standards with security,
performance and resource requirements tailored for the highly-constrained environments these devices find
themselves in.
In 2015 the National Institute of Standards and Technology began a Standardization Process in order to select
one or more Lightweight Cryptographic algorithms. Out of the original 57 submissions ten finalists remain, with
ASCON and Romulus being among the most scrutinized out of them.
In this dissertation I will introduce some concepts required for easy understanding of the body of work, do
an up-to-date revision on the current situation on the standardization process from a security and performance
standpoint, a description of ASCON and Romulus, and new best known analysis, and a comparison of the two,
with their advantages, drawbacks, and unique traits.Os padrÔes criptogråficos tradicionais foram elaborados com um ambiente de computador e servidor em mente.
Com a proliferação de dispositivos de pequenas dimensÔes tanto na Internet of Things, redes de sensores e
sistemas embutidos, apareceu uma necessidade para se definir padrÔes para algoritmos de criptografia leve, com
prioridades de segurança, performance e gasto de recursos equilibrados para os ambientes altamente limitados
em que estes dispositivos operam.
Em 2015 o National Institute of Standards and Technology lançou um processo de estandardização com o
objectivo de escolher um ou mais algoritmos de criptografia leve. Das cinquenta e sete candidaturas originais
sobram apenas dez finalistas, sendo ASCON e Romulus dois desses finalistas mais examinados.
Nesta dissertação irei introduzir alguns conceitos necessårios para uma fåcil compreensão do corpo deste
trabalho, assim como uma revisão atualizada da situação atual do processo de estandardização de um ponto
de vista tanto de segurança como de performance, uma descrição do ASCON e do Romulus assim como as
suas melhores anålises recentes e uma comparação entre os dois, frisando as suas vantagens, desvantagens e
aspectos Ășnicos
Temporal patterns of happiness and information in a global social network: Hedonometrics and Twitter
Individual happiness is a fundamental societal metric. Normally measured
through self-report, happiness has often been indirectly characterized and
overshadowed by more readily quantifiable economic indicators such as gross
domestic product. Here, we examine expressions made on the online, global
microblog and social networking service Twitter, uncovering and explaining
temporal variations in happiness and information levels over timescales ranging
from hours to years. Our data set comprises over 46 billion words contained in
nearly 4.6 billion expressions posted over a 33 month span by over 63 million
unique users. In measuring happiness, we use a real-time, remote-sensing,
non-invasive, text-based approach---a kind of hedonometer. In building our
metric, made available with this paper, we conducted a survey to obtain
happiness evaluations of over 10,000 individual words, representing a tenfold
size improvement over similar existing word sets. Rather than being ad hoc, our
word list is chosen solely by frequency of usage and we show how a highly
robust metric can be constructed and defended.Comment: 27 pages, 17 figures, 3 tables. Supplementary Information: 1 table,
52 figure
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