No abstract

Cryptocurrency is a relatively mature application of blockchain technology. The openness of transaction records provides researchers with the opportunity to analyse and compare various cryptocurrencies. The EOS public chain based on EOS. IO supports millions of transactions per second, with billions of transactions, and provides data analysts with a large quantity of analysable transaction data. Combined with the Ethereum platform data of the same period, this paper focuses on the transaction data in the EOS.IO blockchain and analyses the data in the Ethereum and EOS.IO chains from a complex network perspective. By constructing cumulative networks and time-slicing methods, constructing transaction networks of different scales, and dynamically analysing the laws of transaction network changes over time, we find that many transactions, such as transaction volume and transaction relationships, exhibit heavy-tail characteristics and conform to a power-law distribution. In particular, with the change in time and the growth in network scale, the power-law distribution is time-invariant. Our research can verify and predict the progress of blockchain development. Through graph analysis, we also obtained some other observations and discovered some interesting mathematical characteristics that explain the actual interactions that occurred on the blockchain.

Cryptocurrency based on blockchain technology has gradually become a choice for people to invest in, and several users have participated in the accumulation of massive transaction data. Complete transaction records in blockchains and the openness of data provide researchers with opportunities to mine and analyze data in blockchains. Network modeling and analysis of cryptocurrency transaction records are common methods in blockchain data analysis. The analysis of attribute graphs can provide insights into various economic indicators, illegal activities, and general Internet security, among others. Accordingly, this article aims to summarize and analyze the literature on cryptocurrency transaction data from the perspective of complex networks. To provide systematic guidance for researchers, we put forward a blockchain data analysis framework based on the introduction of the relevant background and reviewed the work from five aspects: blockchain data model, data acquisition on blockchains, existing analysis tools, available insights, and common analysis methods. For each aspect, we introduce the research problems, summarize the methods, and discuss the results and findings. Finally, we present future research points and several open questions in the study of cryptocurrency transaction networks.

Due to the unique characteristics of blockchain, such as decentralization, anonymity, high credibility, and nontampering, blockchain technologies have become an integral part of public data platforms and public infrastructure. The communication between the stakeholders of a given blockchain can be used as a carrier for covert communication under cover of legal transactions, which has become a promising research direction of blockchain technology. Due to the special mechanism of blockchain, some traditional blockchain covert communication schemes are not mature enough. They suffer from various drawbacks, such as weak concealment of secret information, cumbersome identification and screening of special transactions, poor availability, and low comprehensive performance. Therefore, this paper designs a scheme of covert communication in the Bitcoin blockchain, which takes normal transactions as a mask and leverages the Bitcoin transaction mechanism to embed secret information in the public key hash field. Specifically, we propose a novel key update mechanism combined with the hash algorithm to construct a covert channel. It ensures security and can update the channel to prevent the related problems caused by address reuse. We are taking advantage of the feature of Bitcoin that cannot be double-spent to solve the problem of burning bitcoin when paying bitcoin to a fake public key hash. In our scheme, both parties to the communication are anonymous, and the attacker cannot detect the covert data or track the transaction and address. Our proposed scheme was tested in real Bitcoin blockchain network, and the experimental results were analyzed to verify its security, availability, and efficiency.