Blockchain Papers

Yu Wang, Zhenzhen Li, Gaopeng Gou, Gang Xiong · 6 authors

No abstract is available for this record.

Zhang Lejun, Zhijie Zhang, Weizheng Wang, Waqas Rasheed · 7 authors

As an extension of the traditional encryption technology, information hiding has been increasingly used in the fields of communication and network media, and the covert communication technology has gradually developed. The blockchain technology that has emerged in recent years has the characteristics of decentralization and tamper resistance, which can effectively alleviate the disadvantages and problems of traditional covert communication. However, its combination with covert communication thus far has been mostly at the theoretical level. The BLOCCE method, as an early result of the combination of blockchain and covert communication technology, has the problems of low information embedding efficiency, the use of too many Bitcoin addresses, low communication efficiency, and high costs. The present research improved on this method, designed the V-BLOCCE which uses base58 to encrypt the plaintext and reuses the addresses generated by Vanitygen multiple times to embed information. This greatly improves the efficiency of information embedding and decreases the number of Bitcoin addresses used. Under the premise of ensuring the order, the Bitcoin transaction OP_RETURN field is used to store the information required to restore the plaintext and the transactions are issued at the same time to improve the information transmission efficiency. Thus, a more efficient and feasible method for the application of covert communication on the blockchain is proposed. In addition, this paper also provides a more feasible scheme and theoretical support for covert communication in blockchain.

Ghareeb Falazi, Uwe Breitenbücher, Florian Daniel, Andrea Lamparelli · 6 authors

No abstract is available for this record.

Mohamed Seifelnasr, Hisham S. Galal, Amr Youssef

McCorry et al. (Financial Cryptography 2017) presented the first implementation of a decentralized self-tallying voting protocol on Ethereum. However, their implementation did not scale beyond 40 voters since all the computations were performed on the smart contract. In this paper, we tackle this problem by delegating the bulk computations to an off-chain untrusted administrator in a verifiable manner. Specifically, the administrator tallies the votes off-chain and publishes a Merkle tree that encodes the tallying computation trace. Then, the administrator submits the Merkle tree root and the tally result to the smart contract. Subsequently, the smart contract transits to an intermediate phase where at least a single honest voter can contend the administrator’s claimed result if it was not computed correctly. Then, in the worst case, the smart contract verifies the dispute at the cost of an elliptic curve point addition and scalar multiplication, and two Merkle proofs of membership which are logarithmic in the number of voters. This allows our protocol to achieve higher scalability without sacrificing the public verifiability or voters’ privacy. To assess our protocol, we implemented an open-source prototype on Ethereum and carried out multiple experiments for different numbers of voters. The results of our implementation confirm the scalability and efficiency of our proposed solution which does not exceed the current block gas limit for any practical number of voters.

Han Liu, Dezhi Han, Dun Li

IoT devices have some special characteristics, such as mobility, limited performance, and distributed deployment, which makes it difficult for traditional centralized access control methods to support access control in current large-scale IoT environment. To address these challenges, this paper proposes an access control system in IoT named fabric-iot, which is based on Hyperledger Fabric blockchain framework and attributed based access control (ABAC). The system contains three kinds of smart contracts, which are Device Contract (DC), Policy Contract (PC), and Access Contract (AC). DC provides a method to store the URL of resource data produced by devices, and a method to query it. PC provides functions to manage ABAC policies for admin users. AC is the core program to implement an access control method for normal users. Combined with ABAC and blockchain technology, fabric-iot can provide decentralized, fine-grained and dynamic access control management in IoT. To verify the performance of this system, two groups of simulation experiments are designed. The results show that fabric-iot can maintain high throughput in large-scale request environment and reach consensus efficiently in a distributed system to ensure data consistency.

Komal Agrawal

With the advent of IoT, gadgets are now becoming more smart and independent. Truth is that the transformation towards the innovation is in progress yet there are still flaws, mainly in security areas like dependence on the data. Keeping in mind the advancement of IoT in the future, trusting in this vast approaching data source is of great importance. Blockchain is reached up to the position where it became the key innovation that will change the way we share data. Providing trust in conveyed situations, without using any advanced technical team is a development, which could change the way of working of numerous enterprises, the IoT amongst them. We can say with confidence that the concept of Blockchain, which is the technology behind crypto currency [3] Bitcoin [1], introduced a new era in the world of Internet and online services. In this paper, we will talk about develop a secure E-voting system using Blockchain technology where nobody can manipulate the votes and every user can vote only once. This is possible using the advantage of Ethereum smart contracts [2]. Smart contracts make it a powerful tool for the digitization of services in the Ethereum platform. Blockchain with smart contracts develops a safe, cheap, secure and transparent E-voting system. Ethereum and its network are suitable for it. Due to its consistency, large scale use and provision of smart contract logic. E-voting is an application that is possible using Blockchain technology with infused smart contracts. It needs to be digitalized over the Internet & that's what we will be working upon.

Vishal Baraiya, Seema Joshi

blockchain is decentralized immutable ledger technology maintaining integrity. So to conduct tamperproof election it’s one of the approach towards it. Smart contracts are Self executed code that is written on Ethereum platform in blockchain. An E-voting system should be completely secure and does not allow voting twice that is double spending in blockchain. So it should be completely transparent. In research work electronic voting application is implemented and tested using smart contract on Ethereum platform with the help of metamask wallet. The results of ballots and votes will be stored on Ethereum blockchain with the help of consensus algorithm proof of stake. This consensus is used in validating a transaction with concept of majority approval. Current electronic voting system requires a centralized authority to control the procedure from ballot input to result output and for monitoring of election. While blockchain technology provide decentralized system which is open across connected nodes. Blockchain assets provide increased level of system security from hacking and fraud. Every transaction in blockchain is time-stamped and signed digitally with the help of cryptographic algorithms, and it assigns unique hash value to every block so it can be trace easily. Blockchain technology is one of solutions because it embraces a decentralized system and the entire databases are owned by many users. The blockchain technology also has much vulnerability due to which many attacks like 51% attack, Double Spending attack, DDOS attack, Sybil attack, Eclipse attack and Routing attack can be performed on it.

Shengling Wang, Xidi Qu, Qin Hu, Xia Wang · 5 authors

Though voting-based consensus algorithms in blockchain outperform proof-based ones in energy- and transaction-efficiency, they are prone to incur wrong elections and bribery elections. The former originates from the uncertainties of candidates’ capability and availability, and the latter comes from the egoism of voters and candidates. Hence, in this paper, we propose an uncertainty- and collusion-proof voting consensus mechanism, including the selection pressure-based voting algorithm and the trustworthiness evaluation algorithm. The first algorithm can decrease the side effects of candidates’ uncertainties, lowering wrong elections while trading off the balance between efficiency and fairness in voting miners. The second algorithm adopts an incentive-compatible scoring rule to evaluate the trustworthiness of voting, motivating voters to report true beliefs on candidates by making egoism consistent with altruism so as to avoid bribery elections. A salient feature of our work is theoretically analyzing the proposed voting consensus mechanism by the large deviation theory. Our analysis provides not only the voting failure rate of a candidate but also its decay speed. The voting failure rate measures the incompetence of any candidate from a personal perspective by voting, based on which the concepts of the effective selection valve and the effective expectation of merit are introduced to help the system designer determine the optimal voting standard and guide a candidate to behave in an optimal way for lowering the voting failure rate.

Ahmet Kurt, Enes Erdin, Mumin Cebe, Kemal Akkaya · 5 authors

While various covert botnets were proposed in the past, they still lack complete anonymization for their servers/botmasters or suffer from slow communication between the botmaster and the bots. In this paper, we propose a new generation hybrid botnet that covertly and efficiently communicates over Bitcoin Lightning Network (LN), called LNBot. LN is a payment channel network operating on top of Bitcoin network for faster Bitcoin transactions with negligible fees. Exploiting various anonymity features of LN, we designed a scalable two-layer botnet which completely anonymize the identity of the botmaster. In the first layer, the botmaster sends commands anonymously to the C&C servers through LN transactions. Specifically, LNBot allows botmaster's commands to be sent in the form of surreptitious multihop LN payments, where the commands are encoded with ASCII or Huffman encoding to provide covert communications. In the second layer, C&C servers further relay those commands to the bots they control in their mini-botnets to launch any type of attacks to victim machines. We implemented a proof-of-concept on the actual LN and extensively analyzed the delay and cost performance of LNBot. Our analysis show that LNBot achieves better scalibility compared to the other similar blockchain botnets with negligible costs. Finally, we also provide and discuss a list of potential countermeasures to detect LNBot activities and minimize its impacts.

Lei Xu, Isaac M. Markus, I Subhod, Nikhil Nayab

Summary Access control is one of the fundamental security mechanisms of IT systems. Most existing access control schemes rely on a centralized party to manage and enforce access control policies. As blockchain technologies, especially permissioned networks, find more applicability beyond cryptocurrencies in enterprise solutions, it is expected that the security requirements will increase. Therefore, it is necessary to develop an access control system that works in a decentralized environment without compromising the unique features of a blockchain. A straightforward method to support access control is to deploy a firewall in front of the enterprise blockchain application. However, this approach does not take advantage of the desirable features of blockchain. In order to address these concerns, we propose a novel blockchain‐based access control scheme, which keeps the decentralization feature for access control–related operations. The newly proposed system also provides the capability to protect user's privacy by leveraging ring signature. We implement a prototype of the scheme using Hyperledger Fabric and assess its performance to show that it is practical for real‐world applications.

Jianquan Ouyang, Yifan Deng, Huanrong Tang

No abstract is available for this record.

Zhang Jichuan, Jianhong Zhai, Yang Ru, Shuyan Liu

No abstract is available for this record.

Ahmet Kurt, Enes Erdin, Mumin Cebe, Kemal Akkaya · 5 authors

No abstract is available for this record.

Michel B. Verwer, Ioanna Dionysiou, Harald Gjermundrød

No abstract is available for this record.

Alexandra Kugusheva, Yury Yanovich

Amid ongoing digitalization, the use case of electronic voting has naturally arisen, with attempts beginning as early as 2000. Blockchain technology has the potential to bring trust and built-in auditing tools to such systems. This paper presents a prototype of the system for collective voting. It is based on blockchain and linkable ring signatures to ensure the transfer of closed (secret) data without the loss of reliability and with respect for the privacy of group members.

Chang Hyun Roh, Yong Woon Hwang, Im-Yeong Lee

E-government systems have ensured reliable data and prevented the forgery and modulation of that information, and so far, this role has been carried out in traditional centralized management. However, centralized data management has the disadvantage of single point of failure and bottlenecks. Blockchain technology has emerged to solve this problem. It is characterized by decentralization, which has been considered insecure in the past, to ensure the integrity of data. However, there are many problems in applying general blockchain and smart contracts to e-government electronic voting. In this paper, we propose a scheme to guarantee the integrity of voting data and to automate the process of voting and counting by smart contract by applying blockchain and smart contract to provide integrity and automation function to electronic voting.

Yousif Abuidris, Rajesh Kumar, Wang Wenyong

Blockchain technology as a decentralized and distributed public ledger in a P2P network has recently gained much attention. In this technology, a linked block structure is applied, and a trusted consensus mechanism is established to synchronize data modifications, making it possible to develop a tamper-proof digital platform for data storage and sharing. We think that blockchain could be used in various interactive online systems, such as the Internet of Things, supply chain systems, voting systems, etc. The scope of this survey is to shed light on some recent contributions of the security and privacy issues associated with e-voting based on blockchain. At the end of this paper, we provided a comparison for the security and privacy requirements of the existing e-voting systems based on blockchain.

João Pereira dos Santos, Nuno Santos, David Dias

The proliferation of unreliable and biased information is a significant\nproblem on the Internet. To assess the credibility of the information retrieved\nfrom news websites and other sources, users often resort to social platforms\nlooking for confirmation with trustworthy parties. However, users may be faced\nwith considerable obstacles posed by the platform provider, who can prevent\naccess to certain content. This paper presents DClaims, a system that provides\na censorship-resistant distributed service for the exchange of information over\nthe Internet using web annotations. DClaims' fully decentralized architecture\nrelies on Inter-Planetary File System (IPFS) and Ethereum blockchain, both of\nwhich offer desirable censorship resistant properties. DClaims is implemented\nas a web annotations browser extension which allows for the classification of\nnews articles, on news websites. From our evaluation of the system, we conclude\nthat a large scale implementation of the system is practical and economically\nviable.\n

Do, Thuat, Thao Nguyen, Hung Pham

Consensus mechanism is the heart of any blockchain network. Many projects have proposed alternative protocols to improve restricted scalability of Proof of Work originated since Bitcoin. As an improvement of Delegated Proof of Stake, in this paper, we introduce a novel consensus, namely, Delegated Proof of Reputation, which is scalable, secure with an acceptable decentralization. Our innovative idea is replacing pure coinstaking by a reputation ranking system essentially based on ranking theories (PageRank, NCDawareRank and HodgeRank).

Utkarsh Saxena, J. S. Sodhi, Rajneesh Tanwar

The idea of smart home existed from 1970's onwards but has come into the knowledge of researchers and data scientist due to the development in the domain of internet of things (IoT) (Kopetz, 2011), but it still suffers from privacy and security vulnerabilities. Conventional security policies or approaches are not applicable to IoT, mainly due to its decentralised topology and the resource constraints of the majority of its devices (Dorri et al., 2017a). This Paper presents an innovative, novel and decentralised approach that can be used to augment the existing security architecture of a smart home network. Our scheme guarantees both trustworthiness and user privacy preservations.

Michał Pawlak, Aneta Poniszewska-Marańda

There exist many voting solutions, which have different benefits and issues. The most significant difficulties faced by such systems are lack of transparency and auditability. Recently developed blockchain technology may be a solution to these issues. The paper describes the use of intelligent agents and multi-agent system concept for Auditable Blockchain Voting System (ABVS), which integrates e-voting process with blockchain technology into one supervised non-remote internet voting system which is end-to-end verifiable.

Shoushou Ren, Bingyang Liu, Fei Yang, Xinpeng Wei · 6 authors

The Domain Name System (DNS) is one of the most fundamental infrastructures of the Internet. However, due to its design philosophy and implementation architecture, the current DNS still suffers from the centralization problem and the data authenticity problem. In this paper, we analyze these two problems and propose a blockchain-based naming system called blockDNS to solve them simultaneously. In blockDNS, domain names can be applied and transferred freely in a decentralized way. Moreover, a lightweight verification mechanism is also proposed coupled with blockDNS. The verification mechanism allows website clients to verify the authenticity of resolution results with few overheads. Simulation results show that, compared to the Simplified Payment Verification method, blockDNS can cut down the overheads for data authenticity verification from 4.955KBytes to 380Bytes. Moreover, we also present an implementation case of blockDNS, which is compatible with the current naming system and can be deployed incrementally.

Chenfu Xu, Hui Yang, Qinyong Yu, Zesong Li

The development of information and communication technology has influenced every dimension of society, including the way government interacts with citizens. Government bodies at all levels across the country issued a serial of guidelines to promote e-government services' quality and efficiency which include six national standards for electronic certificates. The legal validity of electronic certificates is equal to that of paper certificates issued by authorities at provincial, autonomous regional, municipal levels and related departments. This fact will accelerate the construction of e-government to further benefit people and motivate the market. In this paper, we propose a trusted and flexible electronic certificates catalog sharing (ECCS) system based on consortium blockchain to promote the accessibility and efficiency of e-government services which take advantage of immutability and time-stamping of transaction data in blockchain. Security analysis indicates that ECCS can achieve privacy-preservation of electronic certificates and catalog against unauthorized users, integrity of electronic data and authentication of data source. In comparison with other existing schemes which also achieve electronic certificates sharing services, ECCS has better efficiency in terms of traffic loads, and can fit for all scenarios related to electronic certificates sharing.

Paweł Szałachowski

The TLS protocol is a de facto standard of secure client-server communication on the Internet. Unfortunately, the public-key infrastructure (PKI) deployed by TLS is a weakest-link system introducing hundreds of links (i.e., trusted entities). Consequently, an adversary compromising a single trusted entity can impersonate any website. Notary systems, based on multi-path probing, were early and promising proposals to detect and prevent such attacks. Unfortunately, despite their benefits, they are not widely deployed, mainly due to their long-standing unresolved problems. In this paper, we present Persistent and Accountable Domain Validation (PADVA), which is a next-generation blockchain-based TLS notary service. PADVA keeps notaries auditable and accountable, introduces service-level agreements and mechanisms to enforce them, relaxes availability requirements for notaries, and works with the legacy TLS ecosystem. We implemented and evaluated PADVA, and our experiments indicate its efficiency and deployability.