AFistfulofBitcoinsCharacterizingPaymentsAmongMen.PDFVIP

A Fistful of Bitcoins: Characterizing Payments Among Men with No Names Sarah Meiklejohn Marjori Pomarole Grant Jordan Kirill Levchenko Damon McCoy Geoffrey M. Voelker Stefan Savage University of California, San Diego George Mason University ABSTRACT By far the most intriguing exception to this rule is Bitcoin. First Bitcoin is a purely online virtual currency, unbacked by either phys- deployed in 2009, Bitcoin is an independent online monetary sys- ical commodities or sovereign obligation; instead, it relies on a tem that combines some of the features of cash and existing online combination of cryptographic protection and a peer-to-peer proto- payment methods. Like cash, Bitcoin transactions do not explicitly col for witnessing settlements. Consequently, Bitcoin has the un- identify the payer or the payee: a transaction is a cryptographically- intuitive property that while the ownership of money is implicitly signed transfer of funds from one public key to another. Moreover, anonymous, its flow is globally visible. In this paper we explore like cash, Bitcoin transactions are irreversible (in particular, there is no chargeback risk as with credit cards). However, unlike cash, Bit- this unique characteristic further, using heuristic clustering to group Bitcoin wallets based on evidence of shared authority, and then us-