The technology behind blockchain has attracted a lot of attention. However, this technology is for the most part not well understood. There is no consensus on what benefits it may bring or on how it may fail. A careful look into the technology finds that most of the proposed benefits of so called blockchain technologies do not really come from elements unique to blockchain. Instead, they come f...

We present a provably-secure blockchain protocol based on “proof of stake.” As far as we are aware, this is the first proof of stake blockchain protocol which provides rigorous security guarantees. The security properties of the system are analyzed in the model of [9] and are comparable to the ones possessed by the bitcoin blockchain protocol which utilizes proof of work. Furthermore, an incent...

Background: The rapid development of the blockchain technology and its various applications has rendered it important to understand the guidelines for adopting it. Methods: The comparative analysis method is used to analyze different dimensions of the maturity model, which is mainly based on the commonly used capability maturity model. Results: The blockchain maturity model and its adoption pro...

At the heart of the Bitcoin is a blockchain protocol, a protocol for achieving consensus on a public ledger that records bitcoin transactions. To the extent that a blockchain protocol is used for applications such as contract signing and making certain transactions (such as house sales) public, we need to understand what guarantees the protocol gives us in terms of agents’ knowledge. Here, we p...

Large-scale rumor spreading could pose severe social and economic damages. The emergence of online social networks along with the new media can even make rumor spreading more severe. Effective control of rumor spreading is of theoretical and practical significance. This paper takes the first step to understand how the blockchain technology can help limit the spread of rumors. Specifically, we d...

We show how third-party web trackers can deanonymize users of cryptocurrencies. We present two distinct but complementary attacks. On most shopping websites, third party trackers receive information about user purchases for purposes of advertising and analytics. We show that, if the user pays using a cryptocurrency, trackers typically possess enough information about the purchase to uniquely id...

We consider the problem of creating secure and resourceefficient blockchain networks i.e., enable a group of mutually distrusting participants to efficiently share state and then agree on an append-only history of valid operations on that shared state. This paper proposes a new approach to build such blockchain networks. Our key observation is that an append-only, tamper-resistant ledger (when ...