Blockchain Papers

Mitsuyoshi Imamura, Kazumasa Omote

No abstract is available for this record.

Marwa Chaieb, Souheib Yousfi, Pascal Lafourcade, Riadh Robbana

No abstract is available for this record.

Runnan Tan, Xiangyi Kong, Yu Zhang, Qingfeng Tan · 7 authors

No abstract is available for this record.

Chris Berg, Sinclair Davidson, Jason Potts

Distributed ledgers are institutional technologies that pose complex challenges regarding regulation and inter-jurisdictional competition. This chapter introduces ‘crypto-friendly’ public policy as a way to understand these challenges. Blockchains are relevant to public policy in at least three ways. First, they can be adopted by governments for the provision of public services. Second, many blockchain applications interact with existing regulatory frameworks and may provide new regulatory challenges. Third, they present the possibility of ‘crypto-secession’ as a form of privately provided public goods provision. The chapter applies an institutional theory of regulation to assess how blockchains effect relative institutional costs and guide public policy choices. Blockchain applications such as property rights and identity management are also considered. Finally the chapter considers the possibility of crypto-friendliness as a dimension for international regulatory competition.

Muhammed F. Esgin, Raymond K. Zhao, Ron Steinfeld, Joseph K. Liu · 5 authors

We introduce MatRiCT, an efficient RingCT protocol for blockchain confidential transactions, whose security is based on post-quantum'' (module) lattice assumptions. The proof length of the protocol is around two orders of magnitude shorter than the existing post-quantum proposal, and scales efficiently to large anonymity sets, unlike the existing proposal. Further, we provide the first full implementation of a post-quantum RingCT, demonstrating the practicality of our scheme. In particular, a typical transaction can be generated in a fraction of a second and verified in about 23 ms on a standard PC. Moreover, we show how our scheme can be extended to provide auditability, where a user can select a particular authority from a set of authorities to reveal her identity. The user also has the ability to select no auditing and all these auditing options may co-exist in the same environment. The key ingredients, introduced in this work, of MatRiCT are 1) the shortest to date scalable ring signature from standard lattice assumptions with no Gaussian sampling required, 2) a novel balance zero-knowledge proof and 3) a novel extractable commitment scheme from (module) lattices. We believe these ingredients to be of independent interest for other privacy-preserving applications such as secure e-voting. Despite allowing 64-bit precision for transaction amounts, our new balance proof, and thus our protocol, does not require a range proof on a wide range (such as 32- or 64-bit ranges), which has been a major obstacle against efficient lattice-based solutions. Further, we provide new formal definitions for RingCT-like protocols, where the real-world blockchain setting is captured more closely. The definitions are applicable in a generic setting, and thus are believed to contribute to the development of future confidential transaction protocols in general (not only in the lattice setting).

Harsh Jain, Rajvardhan Oak, Jay Bansal

Blockchain is one of the upcoming technologies in computing. It provides a tamper-proof distributed ledger which ensures integrity and authentication, as well as eliminates the need of a centralized trusted authority. This results in a secure and trusted system observed by the public. Although the blockchain was first applied to cryptocurrencies (which resulted in bitcoin), the features it provides are desirable for several other applications. In this paper, we develop a blockchain-based solution for securely digitizing the voting process. Election process is an important test of democracy and rigging the election may have disastrous consequences. Through our solution, we aim to provide a platform for voters to cast their vote securely online, from their home. The votes will be published in the blockchain, which will be observable by everyone. This would result in a tamper-proof ballot system which would be impossible to manipulate. The anonymity of voters will be maintained. We aim to apply this in the Indian context. We further show how our system meets the requirement of an online voting system, and how it resolves the issues present in current as well as proposed systems for the same.

Geoffroy Couteau, Michael Reichle

No abstract is available for this record.

Dong, Aiqing

Blockchain, as an emerging technology, has become one of the hottest issues of discussion among researchers and businessmen. Different from traditional centralized database architecture where applications use central servers and databases under the authority’s control for information processing, blockchain proposes distributed digital ledgers to store data. This project explores the possibility of using blockchain technology to automate the Singapore general election polling process. Ethereum is chosen to be the blockchain protocol in this case due to its capability in executing smart contracts. For this approach, a smart contract defining general election process will be deployed to a Ethereum blockchain. Users will then connect to the network to monitor the contract. The main advantage of blockchain over the traditional client-server model in this context is system transparency and integrity which enhances the trust level citizens can place on the polling process. However, the fully distributed blockchain approach requires a huge amount of citizen data to be transferred to the distributed ledger for identity verification, which is practically infeasible in a short run due to the amount of work involved as well as citizens’ concern over privacy. In the eyes of this consideration, this project proposes a hybrid model combining the traditional centralized approach for identity verification and access control and the distributed approach for voting.

Jorge Lopes, José Luís Pereira, Jo�ão Varaj�ão

Blockchain is a distributed ledger technology that allows digital assets to be transacted in a peer-to-peer decentralized network. Those transactions are verified and registered by every node of the network, thus creating a transparent and immutable sequence of registered events whose veracity is provided by a consensus protocol. By enabling smart contracts to be deployed into a blockchain platform, the number of possible use cases for this technology improves considerably. Eliminating the need for third parties and, therefore, allowing many processes, in both the public and the private sectors, to become more efficient and economical. Electronic voting systems are one example of a use case that can be improved by the blockchain technology. In this paper, we discuss how blockchain technology can solve major electronic voting systems challenges. Additionally, the components and functionalities of our proposed blockchain based electronic voting system are presented and explained.

Priyanka Pal, K J L Sudharsana, Rohith Balaji S

No abstract is available for this record.

Xiong, Luoyuan

Strong anonymity and transaction privacy for cryptocurrencies that build on top of a permissionless blockchain is a well-known hard problem. The duplication of ledger provides public verifiability while also give rise to deanonymization attacks and unlinkability violations, where users’ real world identities are linked to their
\npseudonymous blockchain accounts. Even though some recently proposed protocols that utilize Ring Signatures [1] or Zero Knowledge Proof [2] have effectively mitigated those attacks, the computational overhead and monetary cost that comes along
\nwith those fancy cryptographic primitives render them less usable, which arguably contribute to their poor adoption.
\nIn this work, we proposed a practical, peer-to-peer, coin mixing protocol in the Ethereum blockchain that significantly enhance transaction privacy and bring back the unlinkability property. The protocol is primarily inspired by CoinShuffle++ [3] and Generalized State Channel [4], and it enables secure, accountable and
\nincentive-compatible shuffling while only requires very weak trust assumption, minimal cost and negligible delay.
\nA complete system specification and theoretical evaluation will be provided while the actual experimental the result will appear in a future update once an end-to-end Proof of Concept is built.

Leyi Shi, Yang Li, Tianxu Liu, Jia Liu · 6 authors

Honeypot technology can be applied to efficiently attract attackers and exhaust their resources. However, the traditional static honeypot is easy to be recognized by anti-honeypot technology. By contrast, most of the dynamic honeypots can simulate the real system in time, thus interacting with an intruder in disguise. In this paper, we employ the dynamic property of honeypot in four kinds of services of our system. However, this dynamic property shows up in a location and identification, indicating that genuine or fake services (honeypots) are changeable in different hosts. Thus, the dynamic property of our system differs from the dynamic honeypot aforementioned. Besides, we adopt the blockchain platform (Ethereum) to decentralize our system and store the port access data by delivering a private chain. To illustrate the effectiveness of our scheme in theory and practice, security analysis, eavesdropping attack, scanning attack, and DoS attack experiments are conducted. The results show that our scheme is valid in safeguarding against network attack.

Chiara Braghin, Stelvio Cimato, Simone Raimondi Cominesi, Ernesto Damiani · 5 authors

No abstract is available for this record.

Stefano Tempesta

No abstract is available for this record.

Jacob D. Leshno, Philipp Strack

No abstract is available for this record.

Hai Wang, Yong Wang, Zigang Cao, Zhen Li · 5 authors

The blockchain, with its own characteristics, has received much attention at the beginning of its birth and been applied in many fields. At the same time, however, its security issues are exposed constantly and cyber attacks have caused significant losses in it. At present, there is little concern and research in the field of network security of the blockchain. This paper introduces the applications of blockchain in various fields, systematically analyzes the security of each layer of the blockchain and possible cyber attacks, expounds the challenges brought by the blockchain to network supervision, and summarizes research progress in the protection technology. This paper is a review of the current security of the blockchain and will effectively help the development and improvement of security technologies of the blockchain.

Denis Kirillov, Vladimir Korkhov, Vadim Petrunin, Mikhail Makarov · 6 authors

No abstract is available for this record.

Jordi Paillissé, Jan Manrique, Guillem Bonet, Alberto Rodríguez-Natal · 6 authors

Inter-domain routing security is of critical importance to the Internet since it prevents unwanted traffic redirections. The current system is based on a Public Key Infrastructure (PKI), a centralized repository of digital certificates. However, the inherent centralization of such design creates tensions between its participants and hinders its deployment. In addition, some technical drawbacks of PKIs delay widespread adoption. In this paper we present IPchain, a blockchain to store the allocations and delegations of IP addresses. IPchain leverages blockchains' properties to decentralize trust among its participants, with the final goal of providing flexible trust models that adapt better to the ever-changing geopolitical landscape. Moreover, we argue that Proof of Stake is a suitable consensus algorithm for IPchain due to the unique incentive structure of this use-case, and that blockchains offer relevant technical advantages when compared to existing systems, such as simplified management. In order to show its feasibility and suitability, we have implemented and evaluated IPchain's performance and scalability storing around 350k IP prefixes in a 2.5 GB chain.

Shaozhuo Li, Na Wang, Xuehui Du, Aodi Liu

No abstract is available for this record.

Yogita Borse, Anushka Chawathe, Deepti Patole, Purnima Ahirao

No abstract is available for this record.

Seyedehmahsa Moosavi, Jeremy Clark

No abstract is available for this record.

Shiyao Gao, Dong Zheng, Rui Guo, Chunming Jing · 5 authors

As an important method of making democratic decisions, voting has always been a topic of social concern. Compared with the traditional, e-voting is widely used in various decision scenarios because of the convenience, easy to participate and low cost. However, the proposed e-voting protocols are at the risk of excessive authority and tampered information, which makes it impossible to achieve true fairness and transparency in e-voting. By combining the blockchain technology, it enables to solve these problems with the decentralization and tamper-resistant features. Moreover, the misoperations of the voters will also affect this fairness, such as voting for non-candidates, abstention or repeated voting. Therefore, to ensure the efficiency of the voting process and maintain the fairness of the voting environment, it is important to append the function of audit in e-voting protocol. This paper proposes an e-voting protocol based on blockchain, which provides transparency in the process of voting. At the same time, this scheme has the ability to audit voters operating incorrectly and resist quantum attacks by adopting the certificateless and code-based cryptography. After performance analysis, our scheme is suitable for the small-scale election and has some advantages in security and efficiency when the number of voters is small.

Mochan Fan, Xiaohong Zhang

Flexible regulation of smart grid is vital for grid operation. This paper proposes a smart grid data aggregation and regulation mechanism based on consortium blockchain, and its signcryption algorithm can be applied to multidimensional data acquisition and multiple receivers in the consortium blockchain. In the process of regulation, the control center, the grid operator, and the equipment supplier receive fixed-height blocks from the blockchain and obtain plaintext from the decryption. Each receiver analyzes the multidimensional data and formulates corresponding control policies for individual users. Grid operators implement user power regulation by feedback on smart contracts. The security analysis and performance comparison show that the proposed scheme has advantages in computing and communication costs while meeting security requirements for confidentiality and data integrity.

Jordi Paillissé, Jordi Subira, Albert López, Alberto Rodríguez-Natal · 7 authors

The specification and enforcement of network-wide policies in a single administrative domain is common in today's networks and considered as already resolved. However, this is not the case for multi-administrative domains, e.g. among different enterprises. In such situation, new problems arise that challenge classical solutions such as PKIs, which suffer from scalability and granularity concerns. In this paper, we present an extension to Group-Based Policy -- a widely used network policy language -- for the aforementioned scenario. To do so, we take advantage of a permissioned blockchain implementation (Hyperledger Fabric) to distribute access control policies in a secure and auditable manner, preserving at the same time the independence of each organization. Network administrators specify polices that are rendered into blockchain transactions. A LISP control plane (RFC 6830) allows routers performing the access control to query the blockchain for authorizations. We have implemented an end-to-end experimental prototype and evaluated it in terms of scalability and network latency.