In known constructions of classical zero-knowledge protocols for NP, either of zero-knowledge or soundness holds only against computationally bounded adversaries. Indeed, achieving both statistical zero-knowledge and statistical soundness at the same time with classical verifier is impossible for NP unless the polynomial-time hierarchy collapses, and it is also believed to be impossible even with a quantum verifier. In this work, we introduce a novel compromise, which we call the certified everlasting zero-knowledge proof for QMA. It is a computational zero-knowledge proof for QMA, but the verifier issues a classical certificate that shows that the verifier has deleted its quantum information. If the certificate is valid, even unbounded malicious verifier can no longer learn anything beyond the validity of the statement. We construct a certified everlasting zero-knowledge proof for QMA. For the construction, we introduce a new quantum cryptographic primitive, which we call commitment with statistical binding and certified everlasting hiding, where the hiding property becomes statistical once the receiver has issued a valid certificate that shows that the receiver has deleted the committed information. We construct commitment with statistical binding and certified everlasting hiding from quantum encryption with certified deletion by Broadbent and Islam [TCC 2020] (in a black box way), and then combine it with the quantum sigma-protocol for QMA by Broadbent and Grilo [FOCS 2020] to construct the certified everlasting zero-knowledge proof for QMA. Our constructions are secure in the quantum random oracle model. Commitment with statistical binding and certified everlasting hiding itself is of independent interest, and there will be many other useful applications beyond zero-knowledge.
Abstract: Evolution and modernization have brought about progress in technology and this has led to the reduction in privacy & internet security due to an increase in cybercrime and threats. As a result of this turn of events, Cryptography is now being used as a means of keeping information of any kind safe from third party individual(s). Research has shown that with the Encryption of information, third party individual(s) have no chance or less chance of getting past this security measure. Hence, Cryptographers keep improving algorithms to make it impossible for a third party to decrypt this information without the key which is where database Privacy and Security come in. The database contains all the information which is a major asset, there are encryptions which can be used at different levels to provide security. Lastly, for encryption algorithms which are breached by unknown third-party individual(s), the zero knowledge of proof helps to figure out the identity of this individual. They are an extremely interesting and useful construct. They are fascinating because of their definition, which is mutually opposed, their applicability is very vast in cryptography; they are used to restrict the malevolent users to work according to the protocol. Zero-knowledge serve as a good medium to understand the problems regarding cryptographic protocols. Keywords: Cipher, Encryption, Decryption, Key, Security, Database, Zero-Knowledge
Ceren KocaoÄullar, Arthur Gervais, Benjamin Livshits
While quantitative automation related to trading crypto-assets such as ERC-20 tokens has become relatively commonplace, with services such as 3Commas and Shrimpy offering user-friendly web-driven services for even the average crypto trader, we have not yet seen the emergence of on-chain trading as a phenomenon. We hypothesize that just like decentralized exchanges (DEXes) that by now are by some measures more popular than traditional exchanges, process in the space of decentralized finance (DeFi) may enable attractive online trading automation options. In this paper we present ChainBot, an approach for creating algorithmic trading bots with the help of blockchain technology. We show how to partition the computation into on- and off-chain components in a way that provides a measure of end-to-end integrity, while preserving the algorithmic "secret sauce". Our system is enabled with a careful use of algorithm partitioning, zero-knowledge proofs and smart contracts. We also show that with layer-2 (L2) technologies, trades can be kept private, which means that algorithmic parameters are difficult to recover by a chain observer. Our approach offers more transparent access to liquidity and better censorship-resistance compared to traditional off-chain trading approaches. We develop a sample ChainBot and train it on historical data, resulting in returns that are up to 2.4x the buy-and-hold strategy, which we use as our baseline. Our measurements show that across 1000 runs, the end-to-end average execution time for our system is 48.4 seconds. We demonstrate that the frequency of trading does not significantly affect the rate of return and Sharpe ratio, which indicates that we do not have to trade at every block, thereby significantly saving in terms of gas fees. In our implementation, a user who invests \$1,000 would earn \$105, and spend \$3 on gas; assuming a user pool of 1,000 subscribers.
Jingchi Li, Shaohua An, Honglin Ji, Xingfeng Li · 6 authors
For high-capacity and short-reach applications, carrier-assisted differential detection (CADD) has been proposed, in which the optical field of a complex-valued double sideband (DSB) signal is reconstructed without using a sharp-edge optical bandpass filter or local oscillator laser. The CADD receiver features a transfer function with periodical nulls in the frequency domain, while the signal-signal beat interference (SSBI) is severely amplified around the frequency nulls of the transfer function. Since the null magnitude at the zero frequency is inevitable, a guard band is required between the carrier and the signal, leading to a higher receiver bandwidth and implementation cost. To reduce the needed guard band, we propose a parallel dual delay-based CADD (PDD-CADD), in which an additional delay is placed parallel to the original delay in the conventional CADD. By this means, the modified transfer function has a sharper roll-off edge around the zero frequency. Consequently, the requirement on the guard band can be relaxed, which maximizes the bandwidth utilization of the system. The parallel delay is first optimized through numerical simulation. We then perform a proof-of-concept experiment to transmit a 100-Gb/s orthogonal frequency division multiplexing (OFDM) 16-ary quadrature amplitude modulation (16-QAM) signal over an 80-km single-mode fiber (SMF). After the fiber transmission, the proposed PDD-CADD can reduce the required guard band from 3 to about 1.2 GHz compared with the single delay-based conventional CADD. To our best knowledge, for the direct detection of a single polarization complex-valued DSB signal without using a sharp-roll-off optical filter, we achieve a record electrical spectral efficiency of 5.9 b/s/Hz.
The vast majority of communication on the Internet and private networks heavily relies on Public-key infrastructure (PKI). One possible solution, to avoid complexities around PKI, is to use Password Authenticated Key-Exchange (PAKE) protocols. PAKE protocols enable a secure communication link between the two parties who only share a low-entropy secret (password). PAKEs were introduced in the 1990s, and with the introduction of the first security models and security proofs in the early 2000s, it was clear that PAKEs have a potential for wide deployment - filling the gap where PKI falls short. PAKEsâ PKI-free nature, resistance to phishing attacks and forward secrecy are just some of the properties that make them interesting and important to study. This dissertation includes three works on various aspects of PAKEs: an attack on an existing PAKE proposal, an application of PAKEs in login (for password leak detection) and authentication protocols (HoneyPAKEs), and a security analysis of the J-PAKE protocol, that is used in practice, and its variants. In our first work, we provide an empirical analysis of the zkPAKE protocol proposed in 2015. Our findings show that zkPAKE is not safe against offline dictionary attacks, which is one of the basic security requirements of the PAKE protocols. Further, we demonstrate an implementation of an efficient offline dictionary attack, which emphasizes that, it is necessary to provide a rigorous security proof when proposing a new protocol. In our second contribution, we propose a combined security mechanism called HoneyPAKE. The HoneyPAKE construction aims to detect the loss of password files and ensures that PAKE intrinsically protects that password. This makes the PAKE part of the HoneyPAKE more resilient to server-compromise and pre-computation attacks which are a serious security threat in a client-server communication. Our third contribution facilitates the wider adoption of PAKEs. In this work, we revisit J-PAKE and simplify it by removing a non-interactive zero knowledge proof from the last round of the protocol and derive a lighter and more efficient version called sJ-PAKE. Furthermore, we prove sJ-PAKE secure in the indistinguishability game-based model, the so-called Real-or-Random, also satisfying the notion of perfect forward secrecy.
The vast majority of communication on the Internet and private networks heavily relies on Public-key infrastructure (PKI). One possible solution, to avoid complexities around PKI, is to use Password Authenticated Key-Exchange (PAKE) protocols. PAKE protocols enable a secure communication link between the two parties who only share a low-entropy secret (password). PAKEs were introduced in the 1990s, and with the introduction of the first security models and security proofs in the early 2000s, it was clear that PAKEs have a potential for wide deployment - filling the gap where PKI falls short. PAKEs' PKI-free nature, resistance to phishing attacks and forward secrecy are just some of the properties that make them interesting and important to study. This dissertation includes three works on various aspects of PAKEs: an attack on an existing PAKE proposal, an application of PAKEs in login (for password leak detection) and authentication protocols (HoneyPAKEs), and a security analysis of the J-PAKE protocol, that is used in practice, and its variants. In our first work, we provide an empirical analysis of the zkPAKE protocol proposed in 2015. Our findings show that zkPAKE is not safe against offline dictionary attacks, which is one of the basic security requirements of the PAKE protocols. Further, we demonstrate an implementation of an efficient offline dictionary attack, which emphasizes that, it is necessary to provide a rigorous security proof when proposing a new protocol. In our second contribution, we propose a combined security mechanism called HoneyPAKE. The HoneyPAKE construction aims to detect the loss of password files and ensures that PAKE intrinsically protects that password. This makes the PAKE part of the HoneyPAKE more resilient to server-compromise and pre-computation attacks which are a serious security threat in a client-server communication. Our third contribution facilitates the wider adoption of PAKEs. In this work, we revisit J-PAKE and simplify it by removing a non-interactive zero knowledge proof from the last round of the protocol and derive a lighter and more efficient version called sJ-PAKE. Furthermore, we prove sJ-PAKE secure in the indistinguishability game-based model, the so-called Real-or-Random, also satisfying the notion of perfect forward secrecy.
Zero-Knowledge proofs (ZKPs) enable proving of mathematical statements, revealing nothing but their validity. We design an authentication sys-tem with a ZKP as a password verification mech-anism within the Extensible Authentication Pro-tocol (EAP) framework. Designing a secure pass-word authentication system requires us to adopt security practices for protecting ourselves against the vulnerabilities of passwords. Integrating said practices is not trivial because of the tight cou-pling with the password verification method.
Most of the existing identity management is the centralized architecture that has to validate, certify, and manage identity in a centralized approach by trusted authorities. Decentralized identity is causing widespread public concern because it enables to give back control of identity to clients, and the client then has the ability to control when, where, and with whom they share their credentials. A decentralized solution atop on blockchain will bypass the centralized architecture and address the single point of the failure problem. To our knowledge, blockchain is an inherited pseudonym but it cannot achieve anonymity and auditability directly. In this paper, we approach the problem of decentralized identity management starting from the designated-verifier anonymous credential (DVAC in short). DVAC would assist to build a new practical decentralized identity management with anonymity and auditability. Apart from the advantages of the conventional anonymous credential, the main advantage of the proposed DVAC atop blockchain is that the issued cryptographic token will be divided into shares at the issue phase and will be combined at the showing credential phase. Further, the smooth projective hash function ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi mathvariant="sans-serif">SPHF</a:mi> </a:math> in short) is regarded as a designated-verifier zero-knowledge proof system. Thus, we introduce the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" id="M2"> <d:mi mathvariant="sans-serif">SPHF</d:mi> </d:math> to achieve the designated verifiability without compromising the privacy of clients. Finally, the security of the proposed DVAC is proved along with theoretical and experimental evaluations.
Yeow Meng Chee, Tuvi Etzion, Han Mao Kiah, Alexander Vardy
<p style='text-indent:20px;'>The Hamming ball of radius <inline-formula><tex-math id="M1">\begin{document}$ w $\end{document}</tex-math></inline-formula> in <inline-formula><tex-math id="M2">\begin{document}$ \{0,1\}^n $\end{document}</tex-math></inline-formula> is the set <inline-formula><tex-math id="M3">\begin{document}$ \mathcal{B}(n,w) $\end{document}</tex-math></inline-formula> of all binary words of length <inline-formula><tex-math id="M4">\begin{document}$ n $\end{document}</tex-math></inline-formula> and Hamming weight at most <inline-formula><tex-math id="M5">\begin{document}$ w $\end{document}</tex-math></inline-formula>. We consider injective mappings <inline-formula><tex-math id="M6">\begin{document}$ \varphi : \{0,1\}^m \to \mathcal{B}(n,w) $\end{document}</tex-math></inline-formula> with the following <i>domination property:</i> every position <inline-formula><tex-math id="M7">\begin{document}$ j \in [n] $\end{document}</tex-math></inline-formula> is dominated by some position <inline-formula><tex-math id="M8">\begin{document}$ i \in [m] $\end{document}</tex-math></inline-formula>, in the sense that if position <inline-formula><tex-math id="M9">\begin{document}$ i $\end{document}</tex-math></inline-formula> in <inline-formula><tex-math id="M10">\begin{document}$ {\mathit{\boldsymbol{x}}} \in \{0,1\}^m $\end{document}</tex-math></inline-formula> is "switched off" (equal <i>zero</i>), then necessarily position <inline-formula><tex-math id="M11">\begin{document}$ j $\end{document}</tex-math></inline-formula> in its image <inline-formula><tex-math id="M12">\begin{document}$ \varphi({\mathit{\boldsymbol{x}}}) $\end{document}</tex-math></inline-formula> is switched off. This property may be described more precisely in terms of a bipartite <i>domination graph</i> <inline-formula><tex-math id="M13">\begin{document}$ G = \bigl([m] \cup [n], E\bigr) $\end{document}</tex-math></inline-formula> with no isolated vertices; for all <inline-formula><tex-math id="M14">\begin{document}$ (i,j) \in E $\end{document}</tex-math></inline-formula> and all <inline-formula><tex-math id="M15">\begin{document}$ {\mathit{\boldsymbol{x}}}\in \{0,1\}^m $\end{document}</tex-math></inline-formula>, we require that <inline-formula><tex-math id="M16">\begin{document}$ x_i = 0 $\end{document}</tex-math></inline-formula> implies <inline-formula><tex-math id="M17">\begin{document}$ y_j = 0 $\end{document}</tex-math></inline-formula>, where <inline-formula><tex-math id="M18">\begin{document}$ {\mathit{\boldsymbol{y}}} = \varphi({\mathit{\boldsymbol{x}}}) $\end{document}</tex-math></inline-formula>. Although such domination mappings recently found applications in the context of coding for high-performance interconnects, to the best of our knowledge, they were not previously studied. The concept of domination mapping is thus interesting from both practical and combinatorial points of view. <p style='text-indent:20px;'>In this paper, we begin with simple necessary conditions for the existence of an <i><inline-formula><tex-math id="M19">\begin{document}$ (m,n,w) $\end{document}</tex-math></inline-formula>-domination mapping <inline-formula><tex-math id="M20">\begin{document}$ \varphi : \{0,1\}^m \to \mathcal{B}(n,w) $\end{document}</tex-math></inline-formula></i>. We then provide several explicit constructions of such mappings, which show that the necessary conditions are also sufficient when <inline-formula><tex-math id="M21">\begin{document}$ w = 1 $\end{document}</tex-math></inline-formula>, when <inline-formula><tex-math id="M22">\begin{document}$ w = 2 $\end{document}</tex-math></inline-formula> and <inline-formula><tex-math id="M23">\begin{document}$ m $\end{document}</tex-math></inline-formula> is odd, or when <inline-formula><tex-math id="M24">\begin{document}$ m \leqslant 3w $\end{document}</tex-math></inline-formula>. One of our main results herein is a proof that the trivial necessary condition <inline-formula><tex-math id="M25">\begin{document}$ | \mathcal{B}(n,w)| \geqslant 2^m $\end{document}</tex-math></inline-formula> is, in fact, sufficient for the existence of an <inline-formula><tex-math id="M26">\begin{document}$ (m,n,w) $\end{document}</tex-math></inline-formula>-domination mapping whenever <inline-formula><tex-math id="M27">\begin{document}$ m $\end{document}</tex-math></inline-formula> is sufficiently large. We also present a polynomial-time algorithm that, given any <inline-formula><tex-math id="M28">\begin{document}$ m $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M29">\begin{document}$ n $\end{document}</tex-math></inline-formula>, and <inline-formula><tex-math id="M30">\begin{document}$ w $\end{document}</tex-math></inline-formula>, determines whether an <inline-formula><tex-math id="M31">\begin{document}$ (m,n,w) $\end{document}</tex-math></inline-formula>-domination mapping exists for a domination graph with an equitable degree distribution.
A verifiable random function (VRF in short) is a powerful pseudo-random function that provides a non-interactively public verifiable proof for the correctness of its output. Recently, VRFs have found essential applications in blockchain design, such as random beacons and proof-of-stake consensus protocols. To our knowledge, the first generation of blockchain systems used inherently inefficient proof-of-work consensuses, and the research community tried to achieve the same properties by proposing proof-of-stake schemes where resource-intensive proof-of-work is emulated by cryptographic constructions. Unfortunately, those most discussed proof-of-stake consensuses (e.g., Algorand and Ouroborous family) are not future-proof because the building blocks are secure only under the classical hard assumptions; in particular, their designs ignore the advent of quantum computing and its implications. In this paper, we propose a generic compiler to obtain the post-quantum VRF from the simple VRF solution using symmetric-key primitives (e.g., non-interactive zero-knowledge system) with an intrinsic property of quantum-secure. Our novel solution is realized via two efficient zero-knowledge systems ZKBoo and ZKB++, respectively, to validate the compiler correctness. Our proof-of-concept implementation indicates that even today, the overheads introduced by our solution are acceptable in real-world deployments. We also demonstrate potential applications of a quantum-secure VRF, such as quantum-secure decentralized random beacon and lottery-based proof of stake consensus blockchain protocol.
Abstract In this work we prove the uniqueness of solutions to the nonlocal linear equation $$L \varphi - c(x)\varphi = 0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>Ï</mml:mi> <mml:mo>-</mml:mo> <mml:mi>c</mml:mi> <mml:mo>(</mml:mo> <mml:mi>x</mml:mi> <mml:mo>)</mml:mo> <mml:mi>Ï</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> in $$\mathbb {R}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>R</mml:mi> </mml:math> , where L is an elliptic integro-differential operator, in the presence of a positive solution or of an odd solution vanishing only at zero. As an application, we deduce the nondegeneracy of layer solutions (bounded and monotone solutions) to the semilinear problem $$L u = f(u)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>u</mml:mi> <mml:mo>=</mml:mo> <mml:mi>f</mml:mi> <mml:mo>(</mml:mo> <mml:mi>u</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> in $$\mathbb {R}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>R</mml:mi> </mml:math> when the nonlinearity is of AllenâCahn type. To our knowledge, this is the first work where such uniqueness and nondegeneracy results are proven in the nonlocal framework when the CaffarelliâSilvestre extension technique is not available. Our proofs are based on a nonlocal Liouville-type method developed by Hamel, Ros-Oton, Sire, and Valdinoci for nonlinear problems in dimension two.
The Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) in 2013-2014 was the most comprehensive analysis of anthropogenic climate change, its impacts, and potential responses. It concluded that climate change is âunequivocalâ and human activities are the dominant cause. Avoidance of âdangerousâ climate change will require sustained substantial reductions of emissions by mid-century and that net emissions decrease to zero before 2100. This paper describes, reviews and explains the place of tourism in AR5 and AR5âs relevance for tourismâs future, including impacts, adaptation, vulnerabilities, and mitigation. Tourismâs position in AR5 has strengthened, particularly with respect to the recognition of transboundary impacts, the sectorâs contribution to climate change and its mitigation requirements. Major regional knowledge gaps persist. A lack of understanding of the integrated impacts of climate change and the effectiveness of adaptation strategies potentially hinders the development of resilient tourism operations and destinations. Uncertainties regarding tourist response to climate change impacts and mitigation policy impede predictions of tourism demand. The implications of different decarbonization pathways for the future of international tourism represent a key knowledge gap. The limited response of key tourism organizations to AR5 contributes to the risks climate change poses to the sector. Keywords: climate change; mitigation; adaptation; emissions; impacts; development Please note that the version provided here is the uncorrected proof version. For the authoritative version please go to the journal website: http://www.tandfonline.com/doi/full/10.1080/09669582.2015.1062021#.VbMDLEV30os
Abstract We introduce the probabilistic two-agent justification logic $\textsf {IPJ}$, a logic in which we can reason about agents that perform interactive proofs. In order to study the growth rate of the probabilities in $\textsf {IPJ}$, we present a new method of parametrizing $\textsf {IPJ}$ over certain negligible functions. Further, our approach leads to a new notion of zero-knowledge proofs.
Attribute-based cryptography becomes one of the hot topics in cryptography, since it can provide fine-grained access control and good privacy. ÎŁ-protocol is a 3-move public-coin honest verifier zero-knowledge proof protocol, and has important applications in many fields of cryptography. Firstly, combining the concept of attribute-based cryptography with the zero-knowledge proof, a notion of attribute-based ÎŁ-protocol is introduced with its formal security model. Secondly, based on the standard ÎŁ-protocol, the trapdoor samplable relation and the smooth secret sharing, a general construction of decentralized attribute-based ÎŁ-protocol and corresponding scheme are proposed with the proofs of its securities. Finally, as the applications of decentralized attribute-based ÎŁ-protocol, general constructions of decentralized attribute-based signature and decentralized attribute-based two-tier signature are presented by Fiat-Shamir transformation, respectively. Some concrete schemes are also presented. Performance analysis shows that the proposed attribute-based two-tier signature scheme has obvious advantages in both sizes and computation costs compared with existing schemes.
In traditional blockchain transactions,privacy protection is to encrypt users' sensitive information under the anonymity mechanism,and a trusted third party is involved to verify the transaction plaintext information.However,once the third party is attacked,the users' transaction information will be divulged.Furthermore,there is no truly trusted third party in a rational state.To better solve the privacy problems in blockchain transactions,and in view of issues of confidentiality verification of the tra-ders' transaction amount under the non-anonymous state,the PVC digital commitment protocol is adopted to hide the transaction amount in the commitment,and a publicly verifiable zero-knowledge proof scheme is established,so that verifiers are able to confidentially verify the legitimacy of the transaction without obtaining sensitive information from the traders.At the same time,the elliptic curve homomorphic encryption feature is used to encrypt the amount,thereby solving the problem of updating the traders' ciphertext ledger.The correctness of the proposed privacy protection scheme is verified and analyzed,and the results shows that compared with the existing schemes,the proposed scheme has the advantages of relatively low computational complexity,strong security and high efficiency.
Classical cryptography has been around for a long time in the documented human history, but most classical ciphers were broken and even solved by hand. Shannon introduced the notion of perfect secrecy that formally defines confidentiality in the information-theoretic sense, which is only possible in the restricted scenarios where the message is no longer than the encryption key. The invention of public-key cryptography (the Diffie-Hellman key exchange protocol in 1976 and the RSA crypto-system in 1977) marks the birth of modern cryptography, allowing parties to exchange messages securely without sharing any secrets in advance. Furthermore, it provides computational security based on the conjectured hardness of mathematical problems such as factorization and the discrete logarithm. Public-key cryptography has found numerous applications in the Internet, financial and banking industry, and blockchains, and it plays a crucial role in protecting information security and asset safety. Unfortunately, in the 1990s, Shor proposed efficient quantum algorithms that solve number-theoretic problems, including factorization and discrete logarithms in polynomial time. Once a quantum computer of a particular scale becomes a reality, it will cause a devastating blow to the existing public-key infrastructure. To deal with such a âquantum crisisâ, academia and industry are looking into the design, analysis and standardization of cryptographic algorithms that can resist quantum computers referred to as post-quantum cryptography (PQC). The National Institute of Standards and Technology (NIST) has been soliciting proposals for the post-quantum public-key algorithms since 2016. More recently, the Chinese Association for Cryptologic Research (CACR) held a competition on designing cryptographic algorithms whose public-key cryptography track focused on post-quantum cryptographic algorithms. Lattice-based cryptography is considered by most to be the mainstream technical route of post-quantum cryptography, which is reflected in the number of proposals (and their percentage of the total) received in the NIST PQC process. To reflect the status quo of post-quantum cryptography, we invite leading experts in this area to contribute three technical perspectives that aim to help readers understand the algorithms, the underlying basic techniques and different technical routes to achieve quantum resistance. The first perspective, presented by Lu and Zhang, introduces public-key cryptographic algorithms whose quantum security is reducible from the conjectured quantum hardness of lattice problems. In particular, they mainly focus on public-key encryption (PKE) and the key encapsulation mechanism (KEM), which are essential building blocks for securing the confidentiality of communication without pre-shared secrets. Both types of crypto-systems are solicited by the NIST PQC standardization and the CACR algorithm design competition. This perspective gives a comprehensive survey on practical lattice-based PKEs/KEMs, and their best-known quantum and classical attacks. Another important post-quantum crypto-system is digital signature, which ensures that three goals of information security are met other than confidentiality, namely, integrity, authentication and non-repudiation. The second perspective is on lattice-based signature by Lyubashevsky. In this perspective, he surveys different techniques in building lattice-based post-quantum crypto-systems, discusses the challenges in overcoming performance issues and gives us state-of-the-art digital signature schemes. In addition to ensuring the âstaticâ security of information in storage and transmission, advanced cryptographic algorithms and protocols can guarantee information security during the computation process (possibly among multiple parties), referred to as privacy-preserving computation. Cryptographic techniques involved in privacy-preserving computation include secure multi-party computation, zero-knowledge proof and fully homomorphic encryption. There is a pressing need to migrate them to the post-quantum era. The third perspective, by Yu and Xie, presents practical instantiations of these algorithms and discusses possible ways to migrate them to their quantum-resistant counterparts. To summarize, post-quantum cryptography has received widespread attention and made significant progress in recent years. Some post-quantum cryptographic algorithms, such as the lattice-based candidate, also have other advantages (e.g., computational efficiency and full homomorphism) over their classical counterparts. Lattice-based cryptography is an emerging field with high theoretical value and wide application, and we encourage young researchers to enter and explore this new and exciting field.
After the General Data Protection Regulation (GDPR) was introduced, some organizations and big data companies shared data without conducting any privacy protection and compliance authentication, which endangered user data security, and were punished financially for this reason. This study proposes a blockchain-based GDPR compliance data sharing scheme, aiming to promote compliance with regulations and provide a tool for interaction between users and service providers to achieve data security sharing. The zero-knowledge Succinct Non-Interactive Arguments of Knowledge (zk-SNARK) algorithm is adopted for protecting data and ensure that the userâs private data can satisfy the individual requirements of the service provider without exposing user data. The proposed scheme ensures mutual authentication through the Proof of Authority consensus based on the Committee Endorsement Mechanism (CEM-PoA), and prevents nodes from doing evil using the reputation incentive mechanism. Theoretical analysis and performance comparison indicate that the scheme meets the confidentiality, availability, and other indicators. It has superiority in efficiency and privacy protection compared with other schemes.
Lattice-based non-interactive zero-knowledge proof has been widely used in one-way communication and can be effectively applied to resist quantum attacks. However, lattice-based non-interactive zero-knowledge proof schemes have long faced and paid more attention to some efficiency issues, such as proof size and verification time. In this paper, we propose the non-interactive zero-knowledge proof schemes from RLWE-based key exchange by making use of the Hash function and public-key encryption. We then show how to apply the proposed schemes to achieve the fixed proof size and rapid public verification. Compared with previous approaches, our schemes can realize better effectiveness in proof size and verification time. In addition, the proposed schemes are secure from completeness, soundness, and zero-knowledge.
Samer Ali Alâshami, Abdullah Al Mamun, Nurulizwa Rashid, Mohammed Al-shami
Microcredit financing is extensively considered as an effective development method for poverty mitigation and women empowerment. Nevertheless, relevant studies reflected opposing outcomes on microfinance effects consisting of positive, zero, and negative impacts. Thus, this research investigated Al-Amal Bankâs microcredit impacts on women empowerment in Yemen, one of the poorest Middle Eastern nations. A panel dataset and primary and secondary data were gathered through household surveys and propensity score matching to restrict intangible variablesâ possible effects. The empirical results revealed that microcredit had a significant positive effect on monthly household incomes and accumulated asset values. Although microcredit facilitated female entrepreneurship and income generation for improved household incomes and expenditure, no influence was found on female household decisions and mobility following the patriarchal system practised in many Arabian nations, including Yemen. Hence, the study finding has theoretically and practically contributed to the body of knowledge in three ways. First, a novel proof of how microcredit interactions affected several Yemeni women empowerment elements was identified. This study also provides new insight into the empowerment theory by explaining how access to microcredit influences numerous features of womenâs economic and social empowerment. Lastly, social and family traditions significantly influenced female attributes and lifestyles by reflecting how communal and family rituals affected microcredit impacts on women empowerment and vice versa. Conversely, this study guides Yemeni policymakers and those from other nations on extending financial services for self-development to reduce poverty and drive women empowerment rather than relying on government and international agencies.
The cutting-edge technology, namely Cloud of Things (CoT) has shaped the existing business process into a new orientation in terms of performance, usability, and reliability. Among different business processes, online education is one of the prime areas where CoT can be used to make it more agile in the context of performance and usability. In this endeavor, a novel methodology has been proposed for an online higher education framework based on CoT. The proposed framework is made agile using Service Oriented Architecture (SOA). Furthermore, in order to make the proposed framework more reliable, a Zero Knowledge Proof (ZKPF) system has been introduced here. The proposed ZKPF algorithm is based on the Hadamard matrix. Experimental results have shown to lay bare the effectiveness of the proposed algorithms.
Verifiable delay functions have found a lot of applications in blockchain technology in recent times. Continuous verifiable delay functions are an improvement over the basic notion of VDFs with recursive capabilities. We are proposing the application of VDF for constructing more space time-efficient provers and simulators required for the iterative non-interactive zero-knowledge systems.
Diego F. Aranha, Sebastian Berndt, Thomas Eisenbarth, Okan Seker · 7 authors
We study masking countermeasures for side-channel attacks against signature schemes constructed from the MPC-in-the-head paradigm, specifically when the MPC protocol uses preprocessing. This class of signature schemes includes Picnic, an alternate candidate in the third round of the NIST post-quantum standardization project. The only previously known approach to masking MPC-in-the-head signatures suffers from interoperability issues and increased signature sizes. Further, we present a new attack to demonstrate that known countermeasures are not sufficient when the MPC protocol uses a preprocessing phase, as in Picnic3.We overcome these challenges by showing how to mask the underlying zero-knowledge proof system due to KatzâKolesnikovâWang (CCS 2018) for any masking order, and by formally proving that our approach meets the standard security notions of non-interference for masking countermeasures. As a case study, we apply our masking technique to Picnic. We then implement different masked versions of Picnic signing providing first order protection for the ARM Cortex M4 platform, and quantify the overhead of these different masking approaches. We carefully analyze the side-channel risk of hashing operations, and give optimizations that reduce the CPU cost of protecting hashing in Picnic by a factor of five. The performance penalties of the masking countermeasures ranged from 1.8 to 5.5, depending on the degree of masking applied to hash function invocations.
Open access
Cryptographic Implementations and Security
Chaos-based Image/Signal Encryption
Physical Unclonable Functions (PUFs) and Hardware Security
No scholarly work is finished without the option of outside sources that fill in as supporting proof for the contentions included the article. Refering to academic sources adds believability to your Write my essay record and hoist its quality. In this manner, compose exposition for me accurately refer to the applicable sources in your record.\n\n \n\nAlongside references, guaranteeing that your article is arranged by a particular scholarly style is additionally vital. From the text dimension to the dispersing between the lines, each minor and significant detail should be appropriately arranged in scholarly expositions. In any case, arranging expositions as per target reference styles isn't simple, particularly for novices.\n\n \n\nFortunately, there are the absolute least expensive article composing administration accessible that offer their types of assistance in record designing the compose my exposition. Understudies can without much of a stretch profit themselves of their administrations to write my essay get their expositions expertly arranged.\n\n \n\nBe that as it may, in the event that you need to learn paper designing as indicated by standard scholarly organizations, there isn't anything to stress over. You should simply foster your knowledge of the numerous reference styles that are utilized in scholastic composition. Gain proficiency with the essential tips and deceives and you are a great idea to go. The rest can be gained from online stages that give itemized rules concerning how to design your papers.\n\n \n\nIn the accompanying area, we have zeroed in on one explicit reference style to assist you with your compose my exposition for me arranging. APA reference style is one of the normally utilized reference designs in scholarly composition. Described underneath is a definite aide of APA design. Just intently follow each progression and you will have your paper designed in APA style in a matter of seconds.\n\n \n\nIn APA designing, the header for the cover sheet is distinctive contrasted with the remainder of the archive. In the header area, on the cover sheet, an extra heading "Running Header" is added trailed by the abbreviated title in Capital letters. A colon (:) is added to isolate the two. This is put on the upper left corner while the page number goes ahead the upper right corner. For the remainder of the archive, the situation of page number remaining parts reliable though the essay writer upper right just comprises of an abbreviated title in capital letters.\n\n \n\n \n\nTo organize your paper in APA style, you need to add a point by point cover page featuring the title of the archive, the Name of the creator, and your institutional connection. A creator note can likewise be added to the lower part of the page. The entirety of this data is adjusted focused on the cover page.\n\n \n\n \n\nThe absolute first thing to feature in your report after the cover page is your title. Each Alphabet of paper composing administration your title heading is promoted. No extra designing is required for the title, then again, actually is adjusted focus to the cover page. For level one heading, it is intense and adjusted focus to the page. For level two heading, it is intense however flushed left to the page.\n\n \n\nEach section in APA arranging starts with a half-inch indent. You can consequently add indents to one side of your passage by squeezing the tab button. The dividing between passages is likewise standard with no extra spaces.\n\n \n\nIn text-references in APA organizing incorporate the last name of the write my paper creator followed continuously of distribution. These two substance are encased in enclosure and isolated by the utilization of the comma.\n\n \n\nFor in-text reference, ensure that you are adding your references as you refer to any source in your paper. Leaving your in-text references for the last can prompt errors. For instance, when I compose my paper, I add references next to each other utilizing some reference programming. It's difficult permits me to deal with my in-text references yet in addition helps me in producing an end-text reference list consequently.\n\n \n\nIt is smarter to organize your substance, whenever you are done with the creative cycle to guarantee it's anything but an article author. An APA designing observes standard arranging with text style Times New Roman in size 12.\n\n \n\nThe content in APA designing is twofold divided.\n\n \n\nAn itemized reference list comes toward the finish of your record. It is smarter to create your references about essay writing service utilizing on the web reference generators or reference programming to save yourself from the problem. Referring to style for each source type varies.\n\n \n\nThese are a portion of the fundamentals for APA arranging. We trust that after these tips, you will actually want to helpfully organize your paper. Best of luck.\n\n \n\n \n\n \n\n \n\n