Bitcoin is a crypto currency with several advantages over previous approaches. Transactions are con®rmed and stored by a peer-to-peer network in a blockchain. Therefore, all transactions are public and soon solutions where designed to increase privacy in Bitcoin Many come with downsides, like requiring a trusted third-party or requiring modi®cations to Bitcoin. In this paper, we compare these a...

This paper introduces a noncausal autoregressive process with Cauchy errors in application to the exchange rates of the Bitcoin electronic currency against the US Dollar. The dynamics of the daily Bitcoin/USD exchange rate series displays episodes of local trends, which can be modelled and interpreted as speculative bubbles. The bubbles may result from the speculative component in the on-line t...

It has been shown that seller ratings given by previous buyers give new customers useful information when making purchasing decisions. Bitcoin, however, is designed to obfuscate the link between buyer and seller with a layer of limited anonymity, thus preventing buyers from finding or validating this information. While this level of anonymity is valued by the Bitcoin community, as Bitcoin moves...

Bitcoin is the first decentralized peer-to-peer electronic virtual asset and payment cryptocurrency, through which, users can transact digital currency directly, without the need for an intermediary (or authority), using a hashed version of cryptographic public keys, as pseudonyms called addresses. The Bitcoin ecosystem was supposed to be anonymous and untraceable. However, transactions from in...

The bitcoin peer-to-peer network has drawn significant attention from researchers, but so far has mostly focused on publicly visible portions of the network, i.e., publicly reachable peers. This mostly ignores the hidden parts of the network: unreachable Bitcoin peers behind NATs and firewalls. In this paper, we characterize Bitcoin peers that might be behind NATs or firewalls from different pe...

We study the problem of malleability of Bitcoin transactions. Our first two contributions can be summarized as follows: (i) we perform practical experiments on Bitcoin that show that it is very easy to maul Bitcoin transactions with high probability, and (ii) we analyze the behavior of the popular Bitcoin wallets in the situation when their transactions are mauled; we conclude that most of them...

Bitcoin, a distributed, cryptographic, digital currency, gained a lot of media attention for being an anonymous e-cash system. But as all transactions in the network are stored publicly in the blockchain, allowing anyone to inspect and analyze them, the system does not provide real anonymity but pseudonymity. There have already been studies showing the possibility to deanonymize bitcoin users b...

Over the last 4 years, Bitcoin, a decentralized P2P cryptocurrency, has gained widespread attention. The ability to create pseudoanonymous financial transactions using bitcoins has made the currency attractive to users who value their privacy. Although previous work has analyzed the degree of anonymity Bitcoin offers using clustering and flow analysis, none have demonstrated the ability to map ...

Bitcoin is a digital currency system introduced in 2008 by an anonymous developer using a pseudonym “Satoshi Nakamoto” [15]. Despite its mysterious origins, Bitcoin became the first cryptographic currency that got widely adopted — as of January 2014 the Bitcoin capitalization is over $ 10 bln. The enormous success of Bitcoin was also widely covered by the media (see e.g. [12], [3], [13], [14]) ...

Bitcoin is a “crypto currency”, a decentralized electronic payment scheme based on cryptography. It implements a particular type of peer-to-peer financial anarchy. It has very recently gained excessive popularity and attracted a lot of attention in the mainstream press and media. Scientific research on this topic is less abundant. A paper at Financial Cryptography 2012 conference explains that ...