Bitcoin is a popular digital currency for online payments, realized as a decentralized peer-to-peer electronic cash system. Bitcoin keeps a ledger of all transactions; the majority of the participants decides on the correct ledger. Since there is no trusted third party to guard against double spending, and inspired by its popularity, we would like to investigate the correctness of the Bitcoin p...

Over recent years, interest has been growing in Bitcoin, an innovation which has the potential to play an important role in e-commerce and beyond. The aim of our paper is to provide a comprehensive empirical study of the payment and investment features of Bitcoin and their implications for the conduct of ecommerce. Since network externality theory suggests that the value of a network and its ta...

Bitcoin was the first currency not controlled by a single entity (Nakamoto 2008). Bitcoin is a cryptocurrency, built on blockchain technology. Initially known to only a few nerds and criminals it now has hundreds of thousands of daily transactions. Bitcoin has achieved values of more than US$15,000 per coin (as of the end of 2017). Rising value attracts attention. For some, Bitcoin is digital f...

The limited size of a block in the Bitcoin blockchain produces a scaling bottleneck. The transaction scalability problem can be addressed by performing smaller transactions off-chain and periodically reporting the results to the Bitcoin blockchain. One such solution is the Lightning Network. Bitcoin is employed by lawful users and criminals. This requires crimes against lawful users as well as ...

Bitcoin is a popular alternative to fiat money, widely used for its perceived anonymity properties. However, recent attacks on Bitcoin’s peer-to-peer (P2P) network demonstrated that its gossip-based flooding protocols, which are used to ensure global network consistency, may enable user deanonymization— the linkage of a user’s IP address with her pseudonym in the Bitcoin network. In 2015, the B...

The Bitcoin network relies on peer-to-peer broadcast to distribute pending transactions and confirmed blocks. The topology over which this broadcast is distributed affects which nodes have advantages and whether some attacks are feasible. As such, it is particularly important to understand not just which nodes participate in the Bitcoin network, but how they are connected. In this paper, we int...

The public nature of the blockchain has been shown to be a severe threat for the privacy of Bitcoin users. Even worse, since funds can be tracked and tainted, no two coins are equal, and fungibility, a fundamental property required in every currency, is at risk. With these threats in mind, several privacy-enhancing technologies have been proposed to improve transaction privacy in Bitcoin. Howev...

The Bitcoin cryptocurrency records its transactions in a public log called the blockchain. Its security rests critically on the distributed protocol that maintains the blockchain, run by participants called miners. Conventional wisdom asserts that the protocol is incentive-compatible and secure against colluding minority groups, i.e., it incentivizes miners to follow the protocol as prescribed....

We propose a new time-release protocol based on the bitcoin protocol and witness encryption. We derive a “public key” from the bitcoin block chain for encryption. The decryption key are the unpredictable information in the future blocks (e.g., transactions, nonces) that will be computed by the bitcoin network. We build this protocol by witness encryption and encrypt with the bitcoin proof-of-wo...

In this project, we attempt to apply machine-learning algorithms to predict Bitcoin price. For the first phase of our investigation, we aimed to understand and better identify daily trends in the Bitcoin market while gaining insight into optimal features surrounding Bitcoin price. Our data set consists of over 25 features relating to the Bitcoin price and payment network over the course of five...