This paper proposes a protocol for Proof of As-sets of a bitcoin exchange using the Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (ZK-SNARK) without revealing either the bitcoin addresses of the exchange or balances associated with those addresses. The proof of assets is a mech-anism to prove the total value of bitcoins the exchange has the authority to spend using its private keys. We construct a privacy-preserving ZK-SNARK proof system to prove the knowledge of the private keys corresponding to the bitcoin assets of an exchange. The ZK-SNARK toolchain helps to convert an NP-Statement for proving the knowledge of the private keys (known to the exchange) into a circuit satisfiability problem. In this protocol, the exchange creates a Pedersen commitment to the value of bitcoins associated with each address without revealing the balance. The simulation results show that the proof generation time, size, and verification time are efficient in practice.
In a series of editorials, Analytical Science Advances will highlight emerging scientists that work in the field of Analytical Sciences. For this first editorial, we have invited Dr. Sam Wouters to contribute to this Q/A. We are keen for anyone working in this field to nominate somebody for a Q&A by sending an email to one of the editors and explaining to us why this person should be highlighted. Sam Wouters joined the Department of Chemical Engineering of the Vrije University Brussels (Brussels, Belgium) in 2012 as an MSc student designing and characterizing novel polymeric stationary phases for liquid chromatography. Later he continued as a PhD student in this department working on the miniaturization of chromatographic systems. Sam's motto is âworking hard and playing hardâ, which in fact means he is conducting cutting-edge research with passion and lots of effort, which has led to an outstanding publication record, while outside work he also enjoys his time organizing great parties, making beautiful travels, etc. After his PhD, he joined Agilent Technologies, an instrument manufacturer that is the frontrunner of many analytical technologies. Only recently he moved back to Belgium and joined the R&D team Janssen Pharmaceutical developing novel analytical workflows for the characterization of emerging (bio-)pharmaceuticals. How did you get involved in the field of analytical sciences? I was not a particularly good student at primary school, but when I started in trajectory called Technical Sciences in Belgium when I was 13, things got more interesting I guess. Chemistry, biology, physics: that seemed to make more sense to me. During a 2nd Master, I was combining polymer science with analytical chemistry, studying the synthesis of polymer monoliths to be used as stationary-phase materials in liquid chromatography. This made me divert from material science into analytical science. Drawn to this field, the following 4 years I combined engineering and analytical chemistry, where the passion of Prof. Eeltink for the latter was certainly inspirational. What was the topic of your phd studies? The main idea was to miniaturize an entire ion chromatography (IC) system on a microfluidic platform, with the aim to minimize band-broadening by integrating all components, and eventually realize a portable system. As this is of course a big endeavor, I focused on the key elements, which are the separation and detection. A first important step was to miniaturize the column. A lot of effort went into the in-house manufacturing polymer chips containing a micromachined microfluidic channel. Optimization of the production process and the development of special metal encasing allowed us to establish a pressure rating up to 400 bar, which is more than suitable to do IC, where larger particles are still common use. The microchannels were packed with existing stationary phase materials. Moreover, I developed an approach to create macroporous interconnected polymer (monolithic) stationary phases in situ in the microchannels. Latex coating of the charged monolithic surface, with nanobeads of opposite charge, allowed me to establish the desired ion-exchange retention and capacity. Another key component in IC is a suppressor, which is used to selectively remove ions from the eluent, making the system compatible with conductivity detection. I constructed a miniaturized chemically regenerated membrane suppressor, replacing sodium ions for protons, based on concentration gradient and diffusion. The protons and the sodium hydroxide in the eluent form water. In this way, full conversion of up to 80 mM NaOH to water was achieved applying flow rates as high as 20 ”l/min, being compatible with the flow rates for the miniaturized column format. Moreover, a flow through ring-electrode detector cell, yielding sub-ppb level limits of detection, was developed, which was integrated at the outlet of the suppressor chip, located below the separation chip. Proof-of-concept was demonstrated with the analysis of minute amount of samples obtained from a 250-year-old Antarctic ice core. What was your biggest achievement during this time? Despite having a challenging and multidisciplinary topic, I believe we got pretty far in developing components, which actually functioned. Next to successfully conducting my core research, at the same time I managed to contribute to the research of other people, which seemed fruitful with an additional 13 papers as a result. I was also able to personally present my own work during six oral lectures at international conferences, which gave me a great opportunity to connect with my peers and establish scientific collaborations. What advice would you give to recent phd graduates? I had the opportunity to learn from and work together with many very talented PhD students and post-docs during my time, as well as renowned researchers from academia and industry such as Prof. Paul Haddad and Chris Pohl, which really lifted the research to a higher level. This opened a lot of doors, so my advice is to actively try to engage with such people at conferences, although I admit it can be a bit scary to approach âgurusâ. Despite the above promotion of collaborations, it can also be a pitfall, and in some cases a reason why I see a lot of people struggling to in the end finalize their own PhD. For me it was important to stay focused on getting my own work done and at a certain point in time to prioritize this. Why did you to decide to join industry after your PHD study? For me, halfway through my PhD it was already clear to me I wanted to go into industry to generate more impact and work on solving relevant issues. There's so much interesting research happening at the universities, but often it ends up in a drawer after the graduation. After a short post-doc period in industry, I joined the R&D team of Agilent Technologies in Germany. The idea that I was part of a team developing new technology in close collaboration with some big pharma companies really made this a very fulfilling job. At the same time, it still stayed a bit distant: I only helped provide others the tools to make the difference. I have now recently joined Jansen R&D to fulfil that desire to join a team, which makes the difference by bringing products to the market that will help people. Which skills were lacking for your position in industry and what changes would you suggest for the academic curriculum? Here, it is probably good to start with the quote of J.R. Oppenheimer, with which I opened my PhD booklet: âNo man should escape our universities without knowing how little he knowsâ. No course can really prepare you for what is coming, as that will also vary greatly on the directions you will follow. There's no one-fits-all solution there, but I do think when it comes down to doing a PhD, what you will end up learning depends on your own drive and the development opportunities your promotor and you can generate. At a certain level, to many people in industry, the PhD shows a certain minimum qualification, but then the question will be: what else can you do? Knowledge is important but being able to convey knowledge and work together with respect bring you a long way. Can you describe current trends in analytical instrumentation for liquid chromatography? Having joined a research laboratory after my time at an instrument company, it has really sunk in: I often have only 1 shot at getting the data. Luckily vendors are aware of this, and they are following the trend towards more intelligence, with the aim of having more simplicity (but not per se below the hood of the system), and eventually the aim of reaching the goal of âzero-failed analysisâ. Examples would be automatic checks of the system suitability and performance, automatic start-up, intelligent solvent-level detection, etc. Apart from that there is also the need to solve complex analytical questions, which often involves using complicated setups, such as 2D-LC. I do believe there has been much progress, in making this much more user-friendly (usually by improving the software), and thus more accessible to a broader public. Another example of really creating enabling technology would be the development of online LC, where the aim is to periodically sample directly from a reactor and have feedback loops in place to control the process. In this field of process analytical technologies, it is again software, which is critical to make the difference between being a nice tool, which can occasionally be used by experts, or something which can really be implemented in industry. The scheduling tool provided with the special sampler of the Agilent 1290 Infinity II Online LC allows to monitor processes easily, be it a 20-min small molecule synthesis reaction, or a 3-week fermentation in a bioreactor where multiple-attributes have to be monitored. Which modern technologies are you currently establishing in your laboratory? I was provided the chance to move into the Pharma industry and join the Drug Metabolism and Pharmacokinetics group at Janssen R&D in Belgium, joining the team of Dr. Filip Cuyckens. As a scientist biotransformations the aim is to study the metabolites circulating in the body, to elucidate their structure using high-resolution mass spectrometry and to establish a metabolic pathway. Eventually this contributes to the reports submitted to the Food and Drug Administration (FDA). Part of my job is also renewing existing technology and introducing novel instrumentation to expand on our capabilities. An important tool for our group is a setup capable of injecting very high volumes of sample, for example, 16 ml of plasma (with 50% organic) onto an liquid chromatographic system by making use of a trapping column. This is then transferred to a system with coupled columns where we do online radio-activity detection and mass spectrometry, or fraction collection in 384 well plates with solid scintillation to perform offline counting with long counting times to detect low amount of radioactivity. Given the trend to dose with less radioactivity, the challenge is to inject more or improve detection limits. To better deal with very polar compounds, solvent effects and matrix effects, the capabilities of the setup will be expanded with at-column dilution, which for example works very well with urine. Our group is non-GxP, which means we have a lot of freedom in our experiments. Doing 4D-LC for peak isolation would be a good example. More fundamental research also takes place; our laboratory for example has an ion trap with an infrared laser to study the spectrum of isolated molecules to aid in structure elucidation. An industry first. Where do you see yourself in 10 years? This is the kind of research group and field where there's so much to do and to learn, and it is not impossible to find me in this laboratory still. Of course, the work will not be the same anymore, as there's always the drive to invest in our analytical capabilities, and at the same time the organizations are changing into being more multi-modality, meaning we will be solving more large-molecules-related questions, next to the small-molecules drugs, which still remain important too. Can you say something about your hobbies outside the laboratory? Work-life balance is obviously important to be on top of your game when at work. As such I like to clear the mind while climbing, it is just you and the rock. I'm mostly interested in traditional climbing, which is a discipline where you basically place all your protection yourself; hence you are fully focused and immersed into it. The technical aspects of that style of climbing make it particularly interesting to me. Next to sporty stuff, I like to study and collect WW1 artefacts. The author declares that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
In recent years, the issue of data privacy has attracted increased attention, and how to achieve effective privacy protection in blockchain is a new research hotspot.In view of the current research status and development trend of blockchain in privacy protection, the privacy protection methods of blockchain in transaction address,prophecy machine and smart contract were explained, and the privacy strategies of blockchain in the protection of basic elements were summarized.Based on high-level literature at home and abroad, two types of blockchain cryptographic protection methods and usage scenarios were analyzed, including special cryptographic primitives and post-quantum cryptography.The advantages and disadvantages of seven cryptographic techniques applicable to current blockchain privacy protection were also reviewed, including attribute-based encryption, special data signature, homomorphic encryption, secure multi-party computation, zero-knowledge proofs, and lattice ciphers.It was concluded that the privacy protection of blockchain applications cannot be achieved without cryptographic technology.Meanwhile, the blockchain privacy protection technologies were analyzed in terms of both basic element protection and cryptographic protection.It was concluded that it was difficult to effectively solve the privacy problem only from the application and contract layers of the blockchain, and various cryptographic technologies should be used to complement each other according to different needs and application scenarios.In addition, according to the current development status of blockchain privacy cryptography, the narrative was developed from blockchain basic element protection and cryptography-based protection.From the perspectives of both endogenous basic element security and exogenous cryptographic privacy security, basic element privacy protection should be studied first, followed by an in-depth analysis of cryptographic protection techniques for blockchain privacy.The strengths and weaknesses and the potential value of the privacy handling aspects of the corresponding safeguards should be measured in terms of the development of technology in conjunction with practical applications, while considering the timeliness of the technology.Finally, an outlook on the future direction of blockchain privacy protection technologies was provided, indicating the issues that need to be addressed in focus.
Aug 1, 2022·2022 IEEE International Conferences on Internet of Things (iThings) and IEEE Green Computing & Communications (GreenCom) and IEEE Cyber, Physical & Social Computing (CPSCom) and IEEE Smart Data (SmartData) and IEEE Congress on Cybermatics (Cybermatics)
Secure comparison is an important problem in the field of secure computing. A classic example is the Millionaires' problem, which is securely compares the wealth of two millionaires without revealing their wealth. However most traditional secure comparison protocol requires autonomous computation among the participants. It is necessary to ensure that the model of the participants is a semi-honest model, otherwise the protocol will not be able to execute correctly. In this paper, we introduce a semi-honest judge to improve the DamgĂ„rd-Geisler-KrĂigaard(DGK) comparison protocol by using techniques such as zero-knowledge proof and homomorphic encryption. The improved protocol is not only applicable to the malicious participant model, but also the introduced judge would not get any information of data. At last, the security analysis shows that the proposed scheme in this paper can guarantee the data fairness of the comparison protocol while ensuring the privacy security of the participants.
Anonymous authentication is an important factor for Internet of Things (loT) applications such as Smart Grids and Vehicle Ad hoc Networks. The zero-knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARK) is one of the popular methods that has been used for transacting anonymously in public blockchains. However, a heavy computational process is involved during the generation of zk-SNARK proofs (zk-SNARKs). This intensive computation is a significant barrier that prevents resource-constrained loT devices from implementing zk-SNARKs for anonymous transactions. Therefore, this paper proposes a public blockchain-based lightweight anonymous authentication platform for low-power loT devices using zk-SNARKs. A lightweight anonymous authentication protocol is designed using the SHA256 hash function. The heavy proving processes of the zk-SNARK protocol are offloaded to a powerful loT machine. A proof of concept has been designed to verify the proposed platform is capable to provide anonymous authentication with the help of zk-SNARKs and InterPlanetary File System. The security of the proposed platform is analysed and has been proved to be resistant to tracking, replay, key disclosure, and desynchronization attacks. The performance of the proposed platform is also evaluated and has been proven to be supported by low-power loT devices.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
The traditional identity authentication method not only brings single point of failure, but also easily leads to privacy leakage. In order to solve the problem of information leakage caused by identity authentication, this paper proposes a consortium blockchain-based minimal signature authentication scheme MDSA. We use the structure of Merkle Tree to generate digital credentials for users. In particular, this scheme combining zero-knowledge proofs to provide compliance proofs for user identity attribute values to further achieve minimal authentication. We propose an attribute-based authentication model. In general, our scheme allows for self-sovereign identity, secure creation, and distributed storage. We use FISCO BCOS-based blockchain prototype system as our testbed, and the evaluations show that MDSA is feasible and secure, with linear increases in credential generation and authentication overhead.
Yuechen Pan, Yiwen Zhao, Xiaoguang Liu, Gang Wang · 5 authors
Aiming at the existence of a trusted third party in the traditional lottery and the privacy leakage of the current blockchain lottery scheme, we propose a fair blockchain-based lottery scheme for privacy protection, called FPLotto. Benefiting from a Lagrange interpolating polynomial over a finite field and a verifiable random function, lottery ticket of all users fairly contributes to the generation of winning numbers which is transparent and verifiable to anyone. The discrete logarithm, the one-way property of hash function and VRF provide security and avoid deliberate control of the lottery draw. Moreover, the mixing protocol based on zero-knowledge proofs hides lottery amount and bonus amount, and cuts off the connection among the lottery buyers and the winners for protecting the privacy of users. The scheme guarantees fairness, verifiability, and privacy without a trusted third party. Additionally, we propose a method of aggregation verification based on PLONK reducing the operating cost of lottery agency and speeding up the draw phase.
2 source records
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Online privacy protection is highly associated with verification since it is a part of communication between users and servers. Because privacy has a probability of leaking out during the transmissions. With a new method without knowing and verifying the privacy, the verification method will have a revolution. The traditional verification pattern can be rewritten. This paper introduces the history of verification or secret protection and specifically discusses the theory of zero-knowledge proof. After pointing out that the disadvantage of zero-knowledge is time-consuming, this paper expends the theory with zk-SNARK which stands for âzero-knowledge succinct non-interactive argument of knowledgeâ. The part of zk-SNARK gives 2 implementations by linear algebra and polynomial. This paper lists 3 applications of zk-SNARK, which are z-cash, filecoin and loopring 3.0 in detail. In the end, this paper presents the advantage of zero-knowledge proof with the comparison of other currencies and discusses the risk of using zero-knowledge proof as contracts.
Cryptographic Implementations and Security
Cryptography and Data Security
Physical Unclonable Functions (PUFs) and Hardware Security
Microgrid research and construction effectively use distributed energy resources to stimulate clean energy devel-opment. Peer-to-peer (P2P) energy trading in microgrids helps create a fully competitive and autonomous energy trading market. Blockchain technology is employed to realize a P2P energy trading framework. However, while public blockchain is generally transparent, energy trading information is sensitive and thus requires a privacy-preserving mechanism. In this paper, we design a privacy-preserving energy trading mechanism by using blockchain and zero-knowledge proofs. A user uploads a commitment to the blockchain instead of the original bid amount, and the zero-knowledge proof of commitment is uploaded into the blockchain. Other participants can verify the correctness of energy trading in each auction match. Our experiments show the design is feasible and efficient in Ethereum although there are more gas consumptions.
Abstract Widely adopted blockchain-based fair data exchange protocol have the following problems in multi-party scenario: 1) in multi-buyer v.s. one seller scenario, the negotiation for data availability verification between the buyer and seller reduces transaction throughput greatly. Besides, malicious buyers can launch DoS attacks to prevent the seller from serving others by requiring lots of data availability proofs. 2) in multi-seller v.s. one buyer scenario where the buyer pays for the merged data of all sellers, current protocols treat this as multiple independent transactions, resulting in excessive on-chain costs. Moreover, current protocols neglect that data ownership establishment on-chain may be tampered since the registration info is in plaintext and submitted through the Internet. This paper proposes multi-party non-interactive atomic fair data exchange protocol based on blockchain to solve the above problems, providing data confidentiality, transaction atomic fairness, data intellectual property right protection, and high efficiency. Specifically, we propose transparent zero knowledge proof-based data verification guaranteeing the data confidentiality and transaction fairness. With the proof computed once and used everywhere, transaction throughput is improved greatly and DoS attacks initiated by malicious buyers is prevented. Moreover, the agent representing multi-seller is introduced to reduce on-chain costs. Furthermore, two-stage on-chain ownership registration is proposed to prevent eavesdroppers from impersonating the owner. Finally, we implement a POC (Proof of Concept) of our protocol as the BADE (Blockchain-based multi-party non-interactive Atomic fair Data Exchange). Experiments show that, our throughput within 12 hours is 50 times that of existing solution\cite{ref10}. And in multi-seller scenario, the on-chain gas costs of our protocol is reduced by 19.9\%-30.5\% in different seller/buyer ratios. The fairness of data exchange is also ensured by extra gas costs of dishonest party.
Aisha Zahid Junejo, Manzoor Ahmed Hashmani, Abdullah Alabdulatif, Mehak Maqbool Memon · 6 authors
Preserving anonymity and confidentiality of transactions has become crucial with widespread of the blockchain technology. Despite of the increased efforts for retaining privacy in blockchain networks, invasion attacks are still surfacing. Most of these attacks do not come from outsiders, but from the resident adversarial nodes. Existence of these insider adversaries lead to damaging of an organizationâs internal network system and information leakage. Consequently, transaction anonymity and confidentiality are compromised. Hence, adversary detection and filtration play a vital role in protecting networks against unforeseen privacy and security threats. Therefore, in this paper, we propose RZee, a cryptographic and statistical privacy preserving model for adversary detection and filtering in blockchain networks. Firstly, RZee exploits zero-knowledge proofs to cryptographically secure the data. Secondly, based on certain identified conditions, RZee captures node behavior and blacklists malicious nodes to restrict those from injecting harmful data into the chain or viewing transactions as they propagate across the network. This adds an additional layer of protecting transactions from unauthorized and malicious intervention. The proposed framework is evaluated based on various privacy attributes as identified by literature. For this evaluation, 4 different types of experiments have been conducted. Further, the comparison of privacy perseverance of RZee with existing benchmark privacy-preserving frameworks is also done. The results depict that performance and privacy preservation in RZee exceeds the rest with an attribute score of 6.774 and a gain margin of 46.5%.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Jun Huang, Debiao He, Yitao Chen, Muhammad Khurram Khan · 5 authors
The development of secure and reliable voting mechanism has attracted more and more attention from academia and industry. Many researchers are trying to design a secure and reliable voting system. However, many existing blockchain-based proposals have more or less problems, such as limited number of participants, weak fault-tolerant mechanisms and inadequate privacy protection, which makes it difficult to apply them to the real world to solve the above problems. Therefore, in this paper, we proposed a blockchain-based self-tallying voting protocol to achieve high available, secure and anonymous voting. More specifically, we adopt threshold secret sharing to deal with abstention problem (this is a difficult problem to solve in self-tallying voting systems). We adopt homomorphic encryption and zero-knowledge proof to achieve anonymity and verifiability of encrypted data. Through the analysis and performance testing, and comparison with existing similar proposals, the results show that our scheme has advantages in security and robustness, and the performance test shows that our scheme has good practicability and scalability.
By using zkSNARKs to prove that values have specific dependent types, it is possible to provably assure compatibility and correctness without revealing sensitive information and extend our trusted computing base well beyond our own system. The approach we developed expands the scope of what non-interactive zero-knowledge proofs can capture to include properties about both the execution and correctness of programs.
Probabilistically Checkable Proofs (PCPs) allows a randomized verifier, with oracle access to a purported proof, to probabilistically verify an input statement of the form âxâLâ by querying only a few proof bits. Zero-Knowledge PCPs (ZK-PCPs) enhance standard PCPs to additionally guarantee that the view of any (possibly malicious) verifier querying a bounded number of proof bits can be efficiently simulated up to a small statistical distance. The first ZK-PCP construction of Kilian, Petrank and Tardos (STOC 1997), and following constructions employing similar techniques, necessitate that the honest verifier makes several rounds of queries to the proof. This undesirable property, which is inherent to their technique, translates into increased round complexity in cryptographic applications of ZK-PCPs. We survey two recent ZK-PCP constructionsâdue to Ishai, Yang and Weiss (TCC 2016-A), and Hazay, Venkitasubramaniam and Weiss (ITC 2021)âin which the honest verifier makes a single round of queries to the proof. Both constructions use entirely different techniques compared to previous ZK-PCP constructions, by showing connections to the seemingly-unrelated notion of leakage resilience. These constructions are incomparable to previous ZK-PCP constructions: while on the one hand the honest verifier only makes a single round of queries to the proof, these ZK-PCPs either obtain a smaller (polynomial) ratio between the query complexity of the honest and malicious verifiers or obtain a weaker ZK guarantee in which the ZK simulator is not necessarily efficient.
YASH RAJPUT, Chaitanya Kale -, Santosh Kumar -, Asam Bhanu Prakash - · 5 authors
Know Your Customer (KYC) verification is an essential regulatory procedure in financial services to prevent fraud, money laundering and other financial crimes. Conventional approaches are centralized, redundant across institutions, and prone to data breaches. This paper presents a decentralized framework that combines blockchain smart contracts and InterPlanetary File System (IPFS) for immutably recording KYC document fingerprints while storing actual documents off-chain. We describe the system architecture, implementation choices, security and privacy considerations, and evaluation metrics. The paper includes a comparison between traditional and blockchainenabled KYC systems and discusses future directions such as Decentralized Identifiers (DIDs) and Zero-Knowledge Proofs(ZKPs).
Traceability and trustiness are two critical issues in the logistics sector. Blockchain provides a potential way for logistics tracking systems due to its traits of tamper resistance. However, it is non-trivial to apply blockchain on logistics because of firstly, the binding relationship between virtue data and physical location cannot be guaranteed so that frauds may exist. Secondly, it is neither practical to upload complete data on the blockchain due to the limited storage resources nor convincing to trust the digest of the data. This paper proposes a traceable and trustable consortium blockchain for logistics T2L to provide an efficient solution to the mentioned problems. Specifically, the authenticated geocoding data from telecom operatorsâ base stations are adopted to ensure the location credibility of the data before being uploaded to the blockchain for the purpose of reliable traceability of the logistics. Moreover, we propose a scheme based on Zero Knowledge Proof of Retrievability (ZK BLS-PoR) to ensure the trustiness of the data digest and the proofs to the blockchain. Any user in the system can check the data completeness by verifying the proofs instead of downloading and examining the whole data based on the proposed ZK BLS- PoR scheme, which can provide solid theoretical verification. In all, the proposed T2L framework is a traceable and trustable logistics system with a high level of security.
We propose a new, unifying framework that yields an array of cryptographic primitives with certified deletion. These primitives enable a party in possession of a quantum ciphertext to generate a classical certificate that the encrypted plaintext has been information-theoretically deleted, and cannot be recovered even given unbounded computational resources. - For X \in {public-key, attribute-based, fully-homomorphic, witness, timed-release}, our compiler converts any (post-quantum) X encryption to X encryption with certified deletion. In addition, we compile statistically-binding commitments to statistically-binding commitments with certified everlasting hiding. As a corollary, we also obtain statistically-sound zero-knowledge proofs for QMA with certified everlasting zero-knowledge assuming statistically-binding commitments. - We also obtain a strong form of everlasting security for two-party and multi-party computation in the dishonest majority setting. While simultaneously achieving everlasting security against all parties in this setting is known to be impossible, we introduce everlasting security transfer (EST). This enables any one party (or a subset of parties) to dynamically and certifiably information-theoretically delete other participants' data after protocol execution. We construct general-purpose secure computation with EST assuming statistically-binding commitments, which can be based on one-way functions or pseudorandom quantum states. We obtain our results by developing a novel proof technique to argue that a bit b has been information-theoretically deleted from an adversary's view once they output a valid deletion certificate, despite having been previously information-theoretically determined by the ciphertext they held in their view. This technique may be of independent interest.
An accumulator is a function that hashes a set of inputs into a short, constant-size string while preserving the ability to efficiently prove the inclusion of a specific input element in the hashed set. A concrete accumulator is constructed by using strong RSA assumption. Thanks to their practical features, accumulators are used in various protocols such as zero-knowledge proofs, group signatures, and blockchain. However, lattice-based accumulators are not as well studied as the strong RSA assumption. In 2019, Ling et al. constructed a lattice-based accumulator that is enable to update the member in the list, called LLNW in this paper. However, the update algorithm of the LLNW scheme is not complete, since it requires recalculation to any member regardless of whether or not the member is updated. In this paper, we propose an efficient update algorithm, called EfficientAccWitUpdate, to LLNW, which enables us to update members more efficiently than that in LLNW. In our method, only a member who updates requires recalculation. Specifically, the number of multiplications required for updating in EfficientAccWitUpdate is$\frac{1}{2}$of LNWX, and the number of additions required for updating in EfficientAccWitUpdate is$\frac{nk+1}{2nk-1}$of LNWX. Consequently, by incorporating the EfficientAccWitUpdate accumulator scheme into the zero-knowledge protocol, group signature, and blockchain, it is possible to realize a more efficient application.
The COVID-19 pandemic has led to a worldwide surge in demand for masks, protective clothing, and other epidemic prevention materials. The lack of epidemic prevention materials has put the lives of frontline health care workers at serious risk. However, epidemic prevention materials are not being distributed fairly and efficiently. This, coupled with the occasional scramble for scarce materials, makes epidemic prevention materials scarcer. The traditional centralized donation model makes it difficult to obtain the demand for materials in a timely manner, and the existing blockchain-based donation systems have not improved the efficiency of material donation. Moreover, most of the donation systems do not consider privacy and security issues. In this paper, we propose a blockchain-based material donation platform designed and implemented through the Ethereum platform. We solve the difficulty of demand acquisition and improve the transparency of the donation process through blockchain; reduce the possibility of a second disaster and improve the efficiency of material distribution through smart contracts; and protect the privacy and security of the donation process through zero-knowledge proof. We validate the security and efficiency of the proposed epidemic donation platform.
User privacy is an attractive and valuable task to the success of blockchain systems. However, user privacy protection's performance and data capacity have not been well studied in existing access control models of blockchain systems because of traceability and openness of the P2P network. This paper focuses on investigating performance and data capacity from a blockchain infrastructure perspective, which adds secondary encryption to shield confidential information in a non-invasive way. First, we propose an efficient asymmetric encryption scheme by combining homomorphic encryption and state-of-the-art multi-signature key aggregation to preserve privacy. Second, we use smart contracts and CA infrastructure to achieve attribute-based access control. Then, we use the non-interactive zero-knowledge proof scheme to achieve secondary confidentiality explicitly. Finally, experiments show our scheme succeeds better performance in data capacity and system than other schemes. This scheme improves availability and robust scalability, solves the problem of multi-signature key distribution and the unlinkability of transactions. Our scheme has established a sound security cross-chain system and privacy confidentiality mechanism and that has more excellent performance and higher system computing ability than other schemes.
Dimitris Mouris, Charles Gouert, Nektarios Georgios Tsoutsos
As integrated circuit (IC) design and manufacturing have become highly globalized, hardware security risks become more prominent as malicious parties can exploit multiple stages of the supply chain for profit. Two potential targets in this chain are third-party intellectual property (3PIP) vendors and their customers. Untrusted parties can insert hardware Trojans into 3PIP circuit designs that can both alter device functionalities when triggered or create a side channel to leak sensitive information such as cryptographic keys. To mitigate this risk, the absence of Trojans in 3PIP designs should be verified before integration, imposing a major challenge for vendors who have to argue their IPs are safe to use, while also maintaining the privacy of their designs before ownership is transferred. To achieve this goal, in this work we employ modern cryptographic protocols for zero-knowledge proofs and enable 3PIP vendors prove an IP design is free of Trojan triggers without disclosing the corresponding netlist. Our approach uses a specialized circuit compiler that transforms arbitrary netlists into a zero-knowledge-friendly format, and introduces a versatile Trojan detection module that maintains the privacy of the actual netlist.
Physical Unclonable Functions (PUFs) and Hardware Security
Integrated Circuits and Semiconductor Failure Analysis