High-volume Bitcoin exchanges less likely to fail, but more likely breached, says study

As of April 2013, Bitcoin's market capitalization had soared to more than $1 billion, making it a frequent target of fraudsters. Bitcoins are encrypted virtual money created by computer programmers and not backed by any country or government.

A traceable form of cyber money, Bitcoins can be purchased and used much like hard currency to pay for goods and services, mostly over the Internet. Part of Bitcoins' attraction is its potential to reduce transaction fees for online purchases, as well as its mathematically-enforced protections against inflation.

Study authors Moore and Christin identified 40 Bitcoin exchanges worldwide that convert the cyber money into 33 hard currencies. Of those 40, 18 have gone out of business. Nine of the 40 experienced security breaches from hackers or other criminal activity, forcing five of them to subsequently close. Another 13 closed without any publicly announced breach, according to Moore and Christin.
From their study, the researchers found the failure rate of Bitcoin exchanges is 45 percent. The median lifetime of an exchange is just over one year, 381 days.

Of the 18 Bitcoin exchanges that closed, in 11 of those cases the authors were able to find evidence of whether or not the customers were reimbursed their money. Five exchanges didn't reimburse their customers. Six claim to have done so.

"The risk of losing funds stored at exchanges is real but uncertain," write Moore and Christin in "Beware the Middleman: Empirical Analysis of Bitcoin-Exchange Risk," which was invited for presentation at the 17th International Financial Cryptography and Data Security Conference held in Okinawa, Japan, April 1-5.