Tuesday last week, two blotter squares of LSD arrived in my apartment’s mailbox. The name on the envelope wasn’t mine, but I did buy them and have them delivered to my house. I did so from the comfort of my desk chair using Silk Road, an anonymous online marketplace that caters to many illicit tastes. I could have just as easily purchased marijuana, MDMA, methamphetamine, cocaine, heroin, any of a variety of prescription and other illegal drugs, firearms, forged documents, amongst others.
Silk Road is not a secret community in the sense that anybody with the right tools can access and use it. Its user interface is like a simpler version of eBay with seller feedback scores, back and forth communication between buyer and seller, categories, and a search bar to help you find what you are looking for. It’s not like Silk Road is in the underground either. Over the last two years it has attracted significant attention in the mainstream media and even from the Senator of West Virginia.
The answer to how such a blatantly illegal service can continue to operate with so much attention is a curious ensemble of online privacy tools, all fundamentally relying on the same cryptographic principles that make your online credit card payments and internet passwords secure.
The first of these tools is Tor, which provides two key components of Silk Road’s continued survival: both the anonymity of the servers hosting the website (in terms of their physical location), and anonymity for the people who visit it. Users of Tor have the source and destination of their internet traffic effectively masked by bouncing it through a network of volunteer computer relays. Encryption is used in each relay bounce to ensure that the active relay knows only the identity of the previous and the next step for the traffic, but no other parts of the chain. Anyone can partake in the relay network – including eavesdropping authorities – but they cannot trace the path of relays to the original source of the illegal traffic. Many Tor relay volunteers have been incorrectly arrested and charged in recent years for appearing to be generating traffic to illegal websites. Despite the precarious legal position of being such a volunteer, there are still many operating and the Tor network continues to function.
The physical location of Silk Road’s servers are hidden because they are not accessible via familiar URLs (e.g. www.facebook.com), but through cryptographic bread-crumb trails along the Tor relay network back to the physical server. These are called ‘hidden services’, and their addresses are often very hard to remember – Silk Road’s old hidden service URL was http://ianxz6zefk72ulzz.onion/index.php (note that that address will not work if you enter it into your web browser – you must be accessing it through Tor). Tor is a free, easily procured and preconfigured software package available for all popular operating systems.
The combination of Tor’s hidden services and anonymous browsing is sometimes collectively referred to as the ‘Deep Web’, probably because its content is not visible in normal search engines, but also quite possibly because of its murky content. It is a useful tool for many brands of criminality besides the Silk Road kind, and is very popular among child pornography distributors.
The second key technological component of Silk Road is the Bitcoin – a secure, anonymous payment system. Bitcoins are digital signatures that represent currency. In theory they work as a currency because they are both hard to forge and easy to transfer (much like a banknote). There are no account numbers, BSBs, or names involved in Bitcoin transactions – only long digital addresses that anyone can quickly and anonymously produce on any computer running the Bitcoin software.
Even though every single transaction is traceable, there is still no way to physically locate or identify a person involved in a transaction from their Bitcoin address. Developed in 2006, Bitcoins have received a huge amount of media attention due to their potential for misuse, namely money laundering and drug dealing. Bitcoins can be purchased with ‘real’ currency at any one of the many Bitcoin exchanges operating on the internet.
Silk Road is not the only site of its kind currently operating in the ‘Deep Web’. It is not the first, and it will not be the last. Silk Road is, however, the boldest, most public step yet in a both disturbing and exciting trend towards a truly free internet, empowered by cryptography, beyond the control of any government or organisation.