Bitcoin’s software could ‘carbon date’ digital information, preventing votes from being changed (Image: Chris Rank/Corbis)

IT HAS been a rocky year for Bitcoin, the online peer-to-peer currency, with the exchange rate soaring from a few cents to over $30 per coin before crashing after a string of thefts, hacks and other setbacks. Coins have since regained a value of around $5. But it is becoming clear that the software could prove at least as useful as the currency itself, underpinning a number of important new technologies.

First, it could be used as a form of “carbon dating” for digital information – something that would make electronic voting more secure. This is possible because of the way Bitcoin records transactions, says Jeremy Clark, a computer scientist at Carleton University in Ottawa, Ontario, Canada.

“The currency’s software could ‘carbon date’ digital information, preventing votes from being changed”


An individual’s bitcoins are registered to one or more addresses, which are alphanumeric sequences that serve as the user’s identity on the P2P network. When a transaction takes place, it is broadcast on the network, effectively creating a public record. The coded address keeps the user’s identity anonymous.

Clark and his colleague Aleksander Essex at the University of Waterloo, also in Ontario, realised they could convert a message – for example, a list of codes that securely link voters to their votes – into a Bitcoin address. Sending a tiny fraction of a bitcoin – a small transaction – to that address would allow the holder of that list to store it in the public record without revealing its contents. When they later publish the message for verification, anyone can repeat the conversion to a Bitcoin address and confirm its age by checking the public record.

Faking Bitcoin’s public record would be very difficult as you’d need more computing power than the rest of the Bitcoin network combined – a feature that ensures the currency’s security.

The pair have used their method, known as CommitCoin, to close a loophole in a voting system they helped develop. In the Scantegrity system, voters receive a confirmation code from the list that is cryptographically linked to their selected candidate and can be used to check on the election website that their vote is counted.

Now, if an unscrupulous election official tries to change votes they would be outed, because the code used to record the vote would change, and would not match up with the BitCoin network entry. “CommitCoin allows you to not trust anyone,” says Clark.

“It plugs that gap,” says Steve Schneider, who researches electronic voting systems at the University of Surrey, UK. He points out that, although such systems aren’t yet widely used, it is important that all security problems are resolved before they replace traditional voting methods.

Another system, Namecoin, could be used to circumvent internet censorship. Launched last year, it uses modified Bitcoin software to provide decentralised domain names for websites. When you enter an address like newscientist.com into a browser, it consults a domain name system (DNS) server to find the site’s numerical address. DNS servers are centrally controlled by the Internet Corporation for Assigned Names and Numbers; Namecoin offers a P2P alternative.

This allows owners of “.bit” domains to get around DNS restrictions such as those proposed in the US Stop Online Piracy Act, which if passed into law would see copyright-infringing sites struck from the DNS record.