Abstract Zero-knowledge succinct non-interactive arguments of knowledge (zk-SNARKs) are the most efficient proof systems in terms of proof size and verification. Currently, Groth’s scheme from EUROCRYPT 2016, $$\textsf{Groth16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Groth</mml:mi> <mml:mn>16</mml:mn> </mml:mrow> </mml:math> , is the state-of-the-art and is widely deployed in practice. $$\textsf{Groth16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Groth</mml:mi> <mml:mn>16</mml:mn> </mml:mrow> </mml:math> is originally proven to achieve knowledge soundness, which does not guarantee the non-malleability of proofs. There has been considerable progress in presenting new zk-SNARKs or modifying $$\textsf{Groth16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Groth</mml:mi> <mml:mn>16</mml:mn> </mml:mrow> </mml:math> to efficiently achieve strong Simulation extractability, which is shown to be a necessary requirement in some applications. In this paper, we revise the Random oracle based variant of $$\textsf{Groth16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Groth</mml:mi> <mml:mn>16</mml:mn> </mml:mrow> </mml:math> proposed by Bowe and Gabizon, BG18, the most efficient one in terms of prover efficiency and CRS size among the candidates, and present a more efficient variant that saves 2 pairings in the verification and 1 group element in the proof. This supersedes our preliminary construction, presented in CANS 2020 (Baghery et al. in CANS 20, volume 12579 of LNCS, Springer, Heidelberg. pp 453-461, 2020), which saved 1 pairing in the verification, and was proven in the generic group model. Our new construction also improves on BG18 in that our proofs are in the algebraic group model with Random Oracles and reduces security to standard computational assumptions in bilinear groups (as opposed to using the full power of the generic group model (GGM)). We implement our proposed simulation extractable zk-SNARK (SE zk-SNARK) along with BG18 in the library, and compare the efficiency of our scheme with some related works. Our empirical experiences confirm that our SE zk-SNARK is more efficient than all previous simulation extractable (SE) schemes in most dimensions and it has very close efficiency to the original $$\textsf{Groth16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Groth</mml:mi> <mml:mn>16</mml:mn> </mml:mrow> </mml:math> .
In cryptography, Zero-knowledge proof (ZKP) is a protocol that enables a party to demonstrate the accuracy of a given statement without revealing any additional information beyond the validity of the statement itself. This protocol ensures both the confidentiality and integrity of the computation, and has therefore become widely utilized in various industries for privacy-preserving, including online age verification and electronic voting. The most computationally demanding component of most Zero Knowledge Proof systems is the Multi-Scalar Multiplication (MSM) module. To address this issue and achieve low power and cost efficient MSM for different applications, a novel heterogeneous MSM architecture, ZodiacMSM, is developed. The architecture utilizes the Pippenger algorithm and a multi-chip design with memory access partitioning, which enables scalable performance for polynomials of various sizes in different ZKP applications. The performance of this architecture increases almost linearly with the number of nodes. ZodiacMSM supports multiple elliptic curves through reconfigurable fully-pipelined point-addition to achieve lower latency and minimize scheduler effort. When evaluated in 28nm, ZodiacMSM is able to achieve 2.3x speedup on MSM with single node and 32x speedup on 16 nodes compared to previous peer-reviewed state-of-the-art ASIC results [8].
Traditional blockchains cannot achieve the same transaction throughput as Web2, so their use cases are limited. Therefore, state sharding has been proposed to improve transaction throughput by dividing the blockchain network and managing states and transactions in parallel. However, Nightshade in the NEAR Protocol, a type of state sharding, provides a rollback protocol to cancel the generation of blocks containing inconsistent transaction results because processing cross-shard transactions (CSTXs) in a 2-phase commit may cause state inconsistency. We present a new attack that interferes with the generation of new blocks by repeatedly executing CSTXs that certainly causes state inconsistency, causing continuous rollback. We also propose a block-generation protocol called Synchro to incorporate all the state changes of each CSTX into the same block by coordinating the block prior to approving transactions in each shard. Synchro eliminates the occurrence of the state inconsistency caused by the CSTXs and the necessity of the rollback protocol. We use zero-knowledge proof to make Synchro scalable in the global validation phase. Although the actual overhead of the zero-knowledge proof has not yet been evaluated, we show that Synchro could achieve the same transaction throughput as Nightshade theoretically, depending on the future innovations in zero-knowledge proof techniques.
Biegon Kipkoech Collins, Alex Kibet, Andrew M. Kahonge
Amidst rapid technological advancement and digital transformation, ensuring privacy and data security is paramount. Governments and digital service providers face the challenge of establishing secure identification systems that protect individuals' personal information while enabling reliable authentication and seamless user experiences. Traditional identification methods often require individuals to disclose sensitive personal information, leading to privacy risks and potential data breaches. Zero-knowledge proofs (ZKPs) have emerged as a promising solution to address these concerns. By leveraging ZKPs, individuals can authenticate their identities or assert specific attributes without revealing sensitive data. This approach holds great potential for preserving privacy while enabling efficient and trustworthy verification processes. This paper explored ZKPs and how governments and digital service providers can utilize this technology to achieve secure identification while upholding privacy. A key focus was prototyping a secure identification protocol using ZKPs. Through practical implementation, this research aimed to demonstrate the reliability and effectiveness of ZKPs in real-world scenarios. Keywords : zero-knowledge proofs, privacy, digital identity, governments, digital services. DOI: 10.7176/ISDE/13-2-06 Publication date: September 30 th 2023
In order to solve the problems of imperfect transaction legitimacy verification strategies for protecting account balances and transaction amounts in privacy protection of consortium blockchain, and the low efficiency of the basic encryption algorithm Paillier, a <sup>+</sup>HomElG zero-knowledge proof protocol for consortium blockchain transfer privacy protection was proposed. A consortium blockchain transfer privacy protection application was constructed based on PBFT, which expounded the consensus interaction scenario of zero-knowledge proof of homomorphic encryption. The transaction amount and balance of account were encrypted by the <sup>+</sup>HomElG algorithm, and the zero-knowledge proof of the ciphertext was designed with the Σ protocol. The non-interactive zero-knowledge was designed through the idea of the Fiat-Shamir algorithm processes such as the proof of equality, the amount of the transaction greater than zero and the balance of the transfer party not less than zero in the proof of range. The protocol was proved to be correct, complete and zero-knowledge under the DDH. A consortium blockchain transfer privacy protection prototype system based on Hyperledger Fabric was constructed. The results verified that the protocol can realize ciphertext transactions to protect balance of account and transaction amount under the condition of non-interactive zero-knowledge proof. When the key length is 3072 bit and the data length is a 12-bit decimal integer, the efficiency of the <sup>+</sup>HomElG algorithm is 150.3 ms, and the efficiency of the proof of equality, the amount of the transaction greater than zero and the balance of the transfer party not less than zero in the proof of range are 482.3 ms, 209.3 ms and 261.3 ms respectively. Compared with the existing protocols, the proposed <sup>+</sup>HomElG algorithm is more efficient, and its transaction legitimacy verification strategies such as equality proof and range proof are more perfect and efficient. The proposed protocol can meet the privacy protection requirements of consortium blockchain transfer transactions.
The effective management of electronic health records (EHRs) is vital in healthcare. However, traditional systems often need help handling data inconsistently, providing limited access, and coordinating poorly across facilities. This study aims to tackle these issues using blockchain technology to improve EHR systems' data security, privacy, and interoperability. By thoroughly analyzing blockchain's applications in healthcare, we propose an innovative solution that leverages blockchain's decentralized and immutable nature, combined with advanced encryption techniques such as the Advanced Encryption Standard and Zero Knowledge Proof Protocol, to fortify EHR systems. Our research demonstrates that blockchain can effectively overcome significant EHR challenges, including fragmented data and interoperability problems, by facilitating secure and transparent data exchange, leading to enhanced coordination, care quality, and cost-efficiency across healthcare facilities. This study offers practical guidelines for implementing blockchain technology in healthcare, emphasizing a balanced approach to interoperability, privacy, and security. It represents a significant advancement over traditional EHR systems, boosting security and affording patients greater control over their health records. Doi: 10.28991/HIJ-2023-04-03-012 Full Text: PDF
Dynamic consent management allows a data subject to dynamically govern her consent to access her data. Clearly, security and privacy guarantees are vital for the adoption of dynamic consent management systems. In particular, specific data protection guarantees can be required to comply with rules and laws (e.g., the General Data Protection Regulation (GDPR)). Since the primary instantiation of the dynamic consent management systems in the existing literature is towards developing sustainable e-healthcare services, in this paper, we study data protection issues in dynamic consent management systems, identifying crucial security and privacy properties and discussing severe limitations of systems described in the state of the art. We have presented the precise definitions of security and privacy properties that are essential to confirm the robustness of the dynamic consent management systems against diverse adversaries. Finally, under those precise formal definitions of security and privacy, we have proposed the implications of state-of-the-art tools and technologies such as differential privacy, blockchain technologies, zero-knowledge proofs, and cryptographic procedures that can be used to build dynamic consent management systems that are secure and private by design.
By making a state of the art on the regulations and standards, in force and in progress, this deliverable aims to better inform the regulatory aspects of the design of reusable packaging and to analyse the barriers and opportunities to implement the reuse of packaging, so as to spot potential conflicts with constraints linked to this purpose. The first part is dedicated to the main definitions useful to understand the subject of packaging reuse. To make a relevant state of the art in the second part, we investigated two major issues which both concern the reuse of packaging, at European and national levels, in countries of BUDDIE-PACK's partners: hygiene on one hand and packaging on the other hand, in order to identify any pain point in the reuse of packaging. It can be noted that all the hygiene regulations that we have identified relate to the food sector and do not include any mention of non-food products, such as home care products, which are operated in the use case of ASEVI. Regulation (EC) N°852/2004 lays down the general rules on the hygiene of foodstuffs and especially requires that containers used for transporting foodstuffs to be designed so that adequate cleaning is possible, and to be dedicated for the transport of foodstuffs. Complementary good practices are also mentioned in the Codex Alimentarius, an internationally recognized collection of food standards, and in the ISO 22000 and EN 15593:2008 standards. In Directive 98/83/EC on the quality of water likely to be used in the food industry, despite microbiological and chemical requirements, a vagueness can be observed on three parameters impacting hygiene, which are the colour of water, its smell and its taste: indeed, the Directive only requires that these parameters must be “acceptable to consumer” and that “no unnatural change” can be observed, which means that non-compliance thresholds may vary according to the stakeholders. Standard EN 17735:2022 is essential to guarantee the safety of washing, as it specifies the hygiene requirements for the operation of commercial dishwashers in a professional environment and also includes the main guidelines for obtaining hygienic results for treated articles. To close the chapter on hygiene, one must note that a standard exists to assess the efficience of disinfectants in the food area through a quantitative test on a nonporous surface, such as steel, but that such a standard does not exist on plastic surfaces. The third part presents the packaging regulations from four angles (design, food contact, production and recycling, non-food products) and an institutional analysis. Directive 94/62/EC, on Packaging and Packaging Waste (PPW), is currently being revised by the European Commission: it should become a Regulation, directly applicable by all Member States, and shall further support the implementation of reusable packaging. The vote is expected in September 2023. It should be noticed that the restrictions set in Directive (EU) 2019/904 SUP (Single-Use Plastic) only concern single-use plastic packaging. Regulation (EU) N°10/2011 regulates the safety of plastic materials in contact with food. It gives guidance on specific migration test methods, including for reusable materials: its limitation is that it considers a low number of reuses, so it does not take into account the possible degradation of the material, such as scratches which are inherent in the prolonged reuse of packaging and which can impact the migrations of substances. The REACH Regulation, also under review, establishes procedures for evaluating information on the properties and hazards of chemical substances. Due to the many substances used in the manufacture of plastics and required to make them sustainable, REACH revision may have an impact on the development of reusable packaging. In Regulation (EU) 2022/1616 setting the operating rules of all recycling stages, it is interesting to remember that recycling schemes, of any material, in a closed and controlled chain may be considered as suitable to recycle waste plastic into food-contact plastic, in the same way as mechanical PET recycling. This principle could be implemented for any reusable packaging provided that it is used in a closed system and that external non-foodstuffs contaminations are avoided. Regulation (EC) N°648/2004 on detergents, such as ASEVI’s products, does not mention any requirement on the packaging. Some of BUDDIE-PACK's partners countries, France, Spain, Germany and The Netherlands, have passed laws to implement reusable packaging, with a focus on food or beverage consumption, on-site or on-the-go. While France explicitly banned single-use packaging in several sectors in addition to the on-site catering, Germany and The Netherlands set less restrictive incentives for on-site and take-away catering, and Spain addressed quantified reuse targets for take-away beverage and beverage sold in food retail stores. Note that the UK's exit from the EU led to the transposition of most of regulations mentioned in this deliverable into national law, without significant differences with European regulations, except the SUP Directive, for which an equivalent legislation is expected in October 2023. Beyond these regulations already adopted to promote the reuse of packaging, this dynamic is much broader than Europe: thus, the United Nations Environment Assembly has created an Intergovernmental Negotiating Committee responsible for drafting a text "legally binding" by October 2024. The work sessions should result in a first draft text by November 2023. The suggestions of NGOs converge on the development of shared logistics infrastructures and user-friendly packaging, the expansion of DRS to encourage consumer engagement, but also the standardisation of LCA methods to ensure data reliability. The NGO Zero Waste Europe also insists on the need to implement economic levers to encourage companies to offer reusable packaging, and consumers to choose it. The fourth part gives more details on the main expected modifications in the regulations being revised, especially the PPW and the REACH Regulations, which could impact the development of reusable packaging. To help provide answers to BUDDIE-PACK use cases, the fifth part summarises the regulations and standards that cover each use case, in order to find all information sources at a glance, to incorporate them into the packaging design and to produce packaging fully adapted to the needs. To conclude with this deliverable, the sixth part explains the main barriers and above all the opportunities, at regulatory, technical, safety, social and economic levels. As the hygiene regulations establish an obligation of results towards the actors of the value chain, and not of means, the reuse of packaging does not conflict with hygiene constraints on condition that each part provides the required health guarantees on its scope. Our innovation approach and its proof of concept should allow to identify risky points in advance and to develop solutions to scale up without risk. The debate on the revision of the REACH Regulation will have to be considered into the SSbD concept. In addition, discussions on the PPW Regulation and the Global Plastic Pollution Treaty may open new perspectives of strategies to implement reusable packaging by the end of 2024. The two major technical obstacles are the lack of knowledge about the ageing of plastics through cycles of use and washing (degradation of polymer chains after heat treatment, repeated sealing or mechanical stress, water abrasion) and logistics (collection of used packaging, storage, transport). The Digital Product Passport should therefore be an effective lever for optimising the return of packaging and its durability. Moreover, the standardisation of packaging, coordinated at a European level in cooperation with EPRs and business operators shall allow an optimisation of transport and storage. Capitalising on the experience of manufacturing and retailing sectors which already reuse their packaging will be decisive, especially on the logistics. Solving safety obstacles will be also essential to develop the reuse of packaging, i.e. defining compliance criteria on rinsing and drying to ensure there is no residue of detergent or water, and investigating the risks of migration of substances and release of microplastics, from a material which has been used multiple times. On the first point, depending on the sector, industrial means allow to prevent food contamination (ventilation, humidity control, ease to clean premises and equipments, specially trained staff, etc.). Capitalising on the experience of actors already involved is also an important action lever, such as bottlers or school catering. Social barriers are difficult to solve because they require changing deep-rooted habits, for both packaging’s users and consumers. Restaurants may be afraid of wasting time in their daily tasks (additional time to handle, store, wash, wipe, etc.). Some of consumers could be reluctant to use a packaging that they gauge it has already been used (scratch, small stain, discoloration, etc.), even if it is clean and safe, which requires a specific pedagogy. Active consumerism can effectively contribute to the proper functioning of the reuse loop and is very rewarding for the consumer, as we see it with the successful development in Europe of DRS. Giving back an economic value to packaging should also prevent waste from being abandoned. Even if their exact role is not yet defined, business operators will have to be strongly involved in the management of the reuse loop in opposition to the management of waste, which is dealt by local authorities. This involvement and the initial investment in packaging will impact their business model. To help them, public policies should support adequate eco-modulations and the development of shared logistics. Various incentives should be also addressed to consumers to encourage them to ch
Nada Amin, John C. Burnham, François Garillot, Rosario Gennaro · 7 authors
We introduce Lurk, a new LISP-based programming language for zk-SNARKs. Traditional approaches to programming over zero-knowledge proofs require compiling the desired computation into a flat circuit, imposing serious constraints on the size and complexity of computations that can be achieved in practice. Lurk programs are instead provided as data to the universal Lurk interpreter circuit, allowing the resulting language to be Turing-complete without compromising the size of the resulting proof artifacts. Our work describes the design and theory behind Lurk, along with detailing how its implementation of content addressing can be used to sidestep many of the usual concerns of programming zero-knowledge proofs.
Jim Woodcock, Mikkel Schmidt Andersen, Diego F. Aranha, Stefan Hallerstede · 11 authors
This report describes the state of the art in verifiable computation. The problem being solved is the following: The Verifiable Computation Problem (Verifiable Computing Problem) Suppose we have two computing agents. The first agent is the verifier, and the second agent is the prover. The verifier wants the prover to perform a computation. The verifier sends a description of the computation to the prover. Once the prover has completed the task, the prover returns the output to the verifier. The output will contain proof. The verifier can use this proof to check if the prover computed the output correctly. The check is not required to verify the algorithm used in the computation. Instead, it is a check that the prover computed the output using the computation specified by the verifier. The effort required for the check should be much less than that required to perform the computation. This state-of-the-art report surveys 128 papers from the literature comprising more than 4,000 pages. Other papers and books were surveyed but were omitted. The papers surveyed were overwhelmingly mathematical. We have summarised the major concepts that form the foundations for verifiable computation. The report contains two main sections. The first, larger section covers the theoretical foundations for probabilistically checkable and zero-knowledge proofs. The second section contains a description of the current practice in verifiable computation. Two further reports will cover (i) military applications of verifiable computation and (ii) a collection of technical demonstrators. The first of these is intended to be read by those who want to know what applications are enabled by the current state of the art in verifiable computation. The second is for those who want to see practical tools and conduct experiments themselves.
Blockchain has become a popular decentralized paradigm for various applications in the zero-trust environment. The core of the blockchain is the consensus protocol, which establishes consensus among all the participants. PoW (Proof-of-Work) is one of the most popular consensus protocols. However, the PoW consensus protocol which incentives the participants to use their computing power to solve a meaningless hash puzzle is continuously questioned as energy-wasting. To address these issues, we propose an efficient and secure consensus protocol based on proof of useful federated learning for blockchain (called FedChain). We first propose a secure and robust blockchain architecture that takes federated learning tasks as proof of work. Then a pool aggregation mechanism is integrated to improve the efficiency of the FedChain architecture. To protect model parameter privacy for each participant within a mining pool, a secret sharing-based ring-all reduce architecture is designed. We also introduce a data distribution-based federated learning model optimization algorithm to improve the model performance of FedChain. At last, a zero-knowledge proof-based federated learning model verification is introduced to preserve the privacy of federated learning participants while proving the model performance of federated learning participants. Our approach has been tested and validated through extensive experiments, demonstrating its performance.
Blockchains are decentralized and immutable databases that are shared among the nodes of the network. Although blockchains have attracted a great scale of attention in the recent years by disrupting the traditional financial systems, the transaction privacy is still a challenging issue that needs to be addressed and analysed. We propose a Private Token Transfer System (PTTS) for the Ethereum public blockchain in the first part of this paper. For the proposed framework, zero-knowledge based protocol has been designed using Zokrates and integrated into our private token smart contract. With the help of web user interface designed, the end users can interact with the smart contract without any third-party setup. In the second part of the paper, we provide security and privacy analysis including the replay attack and the balance range privacy attack which has been modelled as a network flow problem. It is shown that in case some balance ranges are deliberately leaked out to particular organizations or adversial entities, it is possible to extract meaningful information about the user balances by employing minimum cost flow network algorithms that have polynomial complexity. The experimental study reports the Ethereum gas consumption and proof generation times for the proposed framework. It also reports network solution times and goodness rates for a subset of addresses under the balance range privacy attack with respect to number of addresses, number of transactions and ratio of leaked transfer transaction amounts.
Open access
3 source records
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
The privacy-preserving data aggregation is a critical problem for many applications where multiple parties need to collaborate with each other privately to arrive at certain results. Blockchain, as a database shared across the network, provides an underlying platform on which such aggregations can be carried out with a decentralized manner. Therefore, in this paper, we have proposed a scalable privacy-preserving data aggregation protocol for summation on the Ethereum blockchain by integrating several cryptographic primitives including commitment scheme, asymmetric encryption and zero-knowledge proof along with the hypercube network topology. The protocol consists of four stages as contract deployment, user registration, private submission and proof verification. The analysis of the protocol is made with respect to two main perspectives as security and scalability including computational, communicational and storage overheads. In the paper, the zero-knowledge proof, smart contract and web user interface models for the protocol are provided. We have performed an experimental study in order to identify the required gas costs per individual and per system. The general formulation is provided to characterize the changes in gas costs for the increasing number of users. The zero-knowledge proof generation and verification times are also measured.
With the increasing presence of blockchain-based distributed applications in various aspects of daily life, there has been a growing focus on the privacy protection of blockchain ledgers and the corresponding regulatory technologies. However, current mainstream solutions primarily concentrate on the verifiable encryption of blockchain transaction addresses and contents, neglecting the regulatory requirements for private transactions. Moreover, the few monitorable solutions suffer from issues such as excessive centralization and a single-minded approach to regulatory content. To address these deficiencies, this paper proposes a blockchain privacy-preserving scheme that supports multi-level regulation through the utilization of zero-knowledge proofs (zk-SNARKs) and attribute-based encryption (ABE). Firstly, by leveraging zk-SNARKs, this scheme achieves blockchain privacy-preserving within an account model, enabling the concealment of user transaction addresses and values. Secondly, by employing attribute-based encryption, a multi-level regulatory model is developed alongside the privacy protection measures, allowing for selective disclosure of transaction content. Finally, we analyze the security of the proposed scheme and compare it with other schemes, discussing its advantages in terms of privacy, security, and regulatory capabilities, we also provide a preliminary evaluation of the scheme's efficiency through experiments. In conclusion, the scheme demonstrates strong privacy by relying on mathematical proofs through zk-SNARKs to ensure security while comprehensively safeguarding content. It also achieves multi-level regulation on the foundation of privacy protection, with comprehensive regulatory coverage and decentralized regulatory authority.
With the increasing interest for advanced protocols for Multi Party Computation, Fully-Homomorphic Encryption or Zero Knowledge proofs, a need for cryptographic algorithms with new constraints has emerged. These algorithms, called Arithmetization-Oriented ciphers, seek to minimize the number of field multiplications in large finite fields F2n or Fp. Among them, Ciminion is an encryption algorithm proposed by Dobraunig et al. in Eurocrypt 2021. In this paper, we show a new univariate modelization on a variant of Ciminion proposed by the designers. This instance restricts the attacker to at most 2 s/2 data, where s is the security level. Because the designers chose to reduce the number of rounds in that specific attacker model, we are able to attack the cipher for large security levels. We also propose some slight modifications of Ciminion that would overcome this vulnerability.
Abstract: This research paper surveys the landscape of cryptography, encompassing historical origins and modern applications. Beginning with foundational concepts, it explores encryption, decryption, ciphers, and keys, spanning symmetric and asymmetric cryptography. Historical context unfolds, tracing cryptography from ancient Egyptian hieroglyphs to Julius Caesar's cipher. The study then transitions to contemporary subjects. Elliptic Curves and Cryptography are investigated, showcasing their significance in secure communication, demonstrating ECC key exchange and AES-GCM encryption using python and Comparative analysis of ECC, RSA, and Diffie-Hellman sheds light on their performance. Zero-Knowledge Proofs are introduced as tools for privacy-preserving verification followed by an exploration of various Zero-Knowledge Proof (ZKP) protocols. By presenting practical implementation examples using Python, the paper illustrates how these proofs can be applied in real-world scenarios. Random Number Generation is examined and distinction between pseudorandom number generators (PRNGs) and cryptographically secure PRNGs (CSPRNGs) is emphasized conducting a thorough comparative analysis of PRNGs and CSPRNGs, considering factors like correlation, independence, periodicity, and entropy. Furthermore, the section evaluates the performance of different random number generation techniques. Fully Homomorphic Encryption emerges as a groundbreaking concept, discussing its mathematical properties, practical implementation, parameter selection, and optimization techniques enabling computation on encrypted data. Cryptographic Secret Sharing Schemes are explored for secure information distribution. The paper concludes by delving into the Chinese Remainder Theorem's applications within modern cryptographic protocols, particularly in RSA decryption and the integration factorization process of the RSA public key cryptosystem. It also provides a comprehensive overview of the theoretical foundations of primality testing, a pivotal aspect of the RSA algorithm. Overall, this research paper provides a comprehensive exploration of cryptography's historical context, core concepts, advanced techniques, and practical implementations, offering valuable insights into the realm of secure communication
Annisa Dini Handayani, Sa'aadah Sajjana Carita, Nia Yulianti
Zero-knowledge proof is a tool in cryptography that ensures the privacy of the users. In general, zero-knowledge (ZK) proves that a user (called the prover) knows one secret value to another (called the verifier) without revealing the secret value itself. This proof is used, for instance, in password verification or authentication process. The concept of ZK has been implemented in various fileds, including secure multi-party computation and blockchain technology. ZK proof could use pairing as the interactive function, through which the prover and verifier play their roles. ZK proof usually protects one secret, meaning the prover only certifies their knowledge of one single secret value. In this paper, we proposed a zero-knowledge scheme using a bilinear map which could help a user prove their knowledge related to multiple secret values to others. We also show that this scheme satisfies completeness and soundness properties, implying the proposed scheme is a proof of knowledge.
With the rapid development of the Industrial Internet, higher challenges are posed to the data security and privacy protection of traditional industrial Internet data sharing. At the present stage, the industrial Internet field has problems such as the lack of flexibility in access control, the difficulty in ensuring data availability, and the inability of data from different enterprises to circulate efficiently and securely, which hinders the development of the industrial Internet. In response to these challenges, a decentralized data-sharing solution based on CP-ABE is proposed to achieve fine-grained access control of industrial Internet data. To address issues related to centralized data storage and single points of failure, this solution combines distributed storage systems to enable distributed storage under the original data ciphertext and sharing of key ciphertext information chains, suitable for a decentralized industrial Internet data sharing architecture. To achieve the "availability and invisibility" of industrial Internet data, smart contracts and zero-knowledge proof technology are utilized to separate data ownership and data usage rights. Finally, security analysis and simulation experiments are conducted to evaluate the proposed scheme. The results demonstrate that the proposed solution effectively achieves fine-grained data access control while ensuring data security, and integrity, and meeting the increasing demands for industrial Internet data sharing efficiently.
The prosperity of blockchain has pushed various decentralized applications, e.g., cross-regional finance, due to its advantages of openness, immutability, and decentralization. The feature of openness inevitably leads to a serious privacy breach. Recently, various privacy-enhanced works (e.g., Zcash, Monero) were proposed focusing on this problem. However, most existing solutions either aim for the unspent transaction output (UTXO) model, or fail to provide full privacy protection for the account-based model with efficient performance. In this paper, we put forwardLedgerMaze, an efficient privacy-preserving non-interactive zero-knowledge (NIZK) scheme over account-model blockchain. We design a novel scheme calledchequemechanism to cut the link between the sender/receiver relationship. Namely, a sender transfers money to a receiver's cheque, then the receiver can retrieve the cheque among a set of cheques for obfuscation without revealing the original one. We construct several efficient NIZK proofs for initializing the mechanism. Moreover, we further analyze the security properties ofLedgerMaze. Experimental results show thatLedgerMazeachieves comparable performance in communication and computation costs while retaining a full privacy guarantee, compared to previous similar constructions.
With the development of deep learning, the demand for similarity matching between texts in text classification is becoming increasingly high. How to match texts quickly under the premise of keeping private information secure has become a research hotspot. However, most existing protocols currently have full set limitations, and the applicability of these methods is limited when the data size is large and scattered. Therefore, this paper applies the secure vector calculation method for text similarity matching in the case of data without any complete set constraints, and it designs a secure computation protocol of text similarity (SCTS) based on the semi-honest model. At the same time, elliptic-curve cryptography technology is used to greatly improve the execution efficiency of the protocol. In addition, we also analyzed the possibility of the malicious behavior of participants in the semi-honest-model protocol, and further designed an SCTS protocol suitable for the malicious model using the cut-and-choose and zero-knowledge-proof methods. By proposing a security mechanism, this protocol aims to provide a reliable and secure computing solution that can effectively prevent malicious attacks and interference. Finally, through the analysis of the efficiencies of the existing protocols, the efficiencies of the protocols under the malicious model are further verified, and the practical value for text classification in deep learning is demonstrated.
Open access
Cryptography and Data Security
Privacy-Preserving Technologies in Data
Advanced Steganography and Watermarking Techniques
The use of blockchain in various fields is increasing rapidly because of its transparency and decentralisation. However, the transparency and immutability of data on the blockchain have prompted questions about data privacy. The intention of this study is to investigate the many theories and solutions made to deal with data privacy in blockchain applications. This paper covers an overview of privacy-preserving techniques like secure multi-party computation, ring signatures, homomorphic encryption, and zero-knowledge proofs, as well as the concept of local differential privacy in data privacy on blockchain. This paper also covers the data privacy challenges in blockchain applications. Overall, the aim of this article is to furnish the latest research and future trends regarding data privacy in blockchain applications and its importance.