After thefts, Bitcoin wallet heads to HTTPS Tor .onion address

UK-based Bitcoin wallet provider Blockchain has a new .onion address and, like Facebook, it’s got itself a signed SSL certificate to validate its hidden website in an effort to combat thefts against its users.

Blockchain, the maker of the world’s most popular Bitcoin wallet, has followed Facebook down the path of the so-called ‘dark web’ — where sites or hidden services with a .onion suffix are not accessible by standard web browsers.

Onion addresses are referred to as the dark web, in particular when law enforcement links a Tor hidden service to more nefarious activities on the web, such as those the alleged operators of the recently seized Silk Road and Silk Road 2.0 marketplaces have been accused of.

Facebook’s arrival as a hidden service illustrated they could also facilitate access to a site from nations where it is censored, such as China and Iran.

Blockchain’s hidden service on the other hand was a response to a spate of attacks on users of its wallet who’d accessed its site through the The Onion Network (Tor) browser.

As Blockchain noted in October following the thefts, Tor users can be stung by malicious Tor exit relays, which allow attackers to stand between the browser and server and ultimately steal their wallet credentials.

The exit relay problem was so bad, according to Australian entrepreneur and security researcher Nik Cubrilovic, that Blockchain blocked all traffic to its wallet from Tor exit nodes.

Blockchain’s new .onion address is “blockchainbdgpzk.onion”, which is accessible from a specially configured version of Firefox known as the Tor Browser.

“If you choose to use Tor, we strongly advise that you access it via blockchainbdgpzk.onion and check your address bar to ensure you are on a valid and trusted connection to the Tor network,” Blockchain’s comms manager Alyson Margaret said.

Blockchain has also emulated Facebook’s model for its .onion address, creating an easily recognisable or ‘vanity’ address. (Facebook’s hidden address is facebookcorewwwi.onion).

And like Facebook, Blockchain acquired its SSL/TLS certificate from the certificate authority (CA) [[xref:http://www.cso.com.au/article/559147/digicert-considering-ssl-certificates-more-tor-hidden-services/|DigiCert.

The SSL certificate is where Cubrilovic’s work, which began on Saturday, comes in to play. Cubrilovic has detailed some of the effort that went into acquiring its ‘vanity’ address here. Blockchain had previously announced “blockchatvqztbll.onion” as its hidden address.

“The main result of these efforts is that today we are announcing that Blockchain is now available as a hidden service on Tor with a signed SSL certificate (provided by DigiCert) and HTTPS enforced across the site,” Cubrilovic noted on his blog.

“With an authenticated hidden service Blockchain users are able to access their Bitcoin wallets with the added anonymity of Tor while avoiding exit nodes,” he added.

However, Cubrilovic notes that the DigiCert certificate used to sign Blockchain’s .onion address might only be valid until November 2015 since .onion is not a recognised top level domain.

This article is brought to you by Enex TestLab, content directors for CSO Australia.

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