Since its inception in early 2009, Bitcoin has attracted a substantial amount of users and the popularity of this decentralised virtual currency is rapidly increasing day by day. Over the years, an arms race for mining hardware has resulted with miners requiring more and more hashing power in order to remain alive in the Bitcoin mining arena. The hashing rate and the energy consumption of the m...

Bitcoin is an international peer-to-peer traded crypto-currency which exhibits high volatility and is minimally impacted by current world events. Bitcoins are directly traded between individuals through intermediate sites that act as bitcoin markets. The largest of these markets is Bitstamp.net. In these markets people offer to buy or sell bitcoin at prices they define, or can put in a fill ord...

The digital currency Bitcoin has had remarkable growth since it was first proposed in 2008. Its distributed nature allows currency transactions without a central authority by using cryptographic methods and a data structure called the blockchain. In this paper we use the no-cloning theorem of quantum mechanics to introduce Quantum Bitcoin, a Bitcoinlike currency that runs on a quantum computer....

Bitcoin, as a cryptocurrency and an alternative payment solution has gained popularity in certain circles. Existing literature offers discussions that are very specific, oftentimes about Bitcoin-related technical issues, but few takes the perspective of an overview that offers an understanding of how Bitcoin may work to the potential user. Though some level of technical understanding is require...

Although Bitcoin is often perceived to be an anonymous currency, research has shown that a user’s Bitcoin transactions can be linked to compromise the user’s anonymity. We present solutions to the anonymity problem for both transactions on Bitcoin’s blockchain and off the blockchain (in so called micropayment channel networks). We use an untrusted third party to issue anonymous vouchers which u...

We propose a formal model of Bitcoin transactions, which is sufficiently abstract to enable formal reasoning, and at the same time is concrete enough to serve as an alternative documentation to Bitcoin. We use our model to formally prove some well-formedness properties of the Bitcoin blockchain, for instance that each transaction can only be spent once. We release an open-source tool through wh...

Bitcoin is a distributed digital currency which has attracted a substantial number of users. We perform an in-depth investigation to understand what made Bitcoin so successful, while decades of research on cryptographic e-cash has not lead to a large-scale deployment. We ask also how Bitcoin could become a good candidate for a long-lived stable currency. In doing so, we identify several issues ...

Bitcoin [2] is a decentralized digital currency which relies neither on banks nor on any other central authority for issuing of coins or transaction verification. Currently, Bitcoin experiences enormous success driven by large interest from users, politics, but also by speculation. Particularly, despite being conjured to be a giant bubble, the value of a bitcoin increased from USD $5 in May 201...

Bitcoin provides freshness properties by forming a blockchain where each block is associated with its timestamp and the previous block. Due to these properties, the Bitcoin protocol is being used as a decentralized, trusted, and secure timestamping service. Although Bitcoin participants which create new blocks cannot modify their order, they can manipulate timestamps almost undetected. This und...

In recent years, Bitcoin, a peer-to-peer network based crypto digital currency, has attracted a lot of attentions from the media, the academia, and the general public. A user in Bitcoin network can create Bitcoins by packing and verifying new transactions in the network using their computation power. Driven by the price surge of Bitcoin, users are increasingly investing on expensive specialized...