The Persona system was first launched as an experimental project called BrowserID in July 2011 with the goal of eliminating the need of creating and managing individual usernames and passwords for different websites.
Persona authenticates users against websites that support the system by using only their existent email addresses.
Users need to first create an account on Mozilla’s persona.org website, define a password and add one or more email addresses to their accounts. The ownership of each individual email address is verified by clicking on a link sent to it.
After that, signing into a website that supports Persona authentication is only a two-click process. Users who are not already logged into persona.org will need to input both their email and Persona password during the sign-in process, while users who are already authenticated will only be asked to select which verified email address they want to use.
Persona is conceptually similar to other authentication systems like OpenID that also allow users to authenticate on different websites using verified identities.
However, Persona relies on public key cryptography operations performed at the browser level without the identity provider – in this case the email provider – being involved in the actual authentication process as with OpenID.
This means that Persona provides a greater level of privacy as the system doesn’t track the activity of its users across the web. “It creates a wall between signing you in and what you do once you’re there. The history of what sites you visit is stored only on your own computer,” Mozilla said on the persona.org website.
However, there are some drawbacks. While eliminating the need to remember separate usernames and passwords for every single website, Persona creates a single point of failure – the persona.org password.
If a user’s Persona password is stolen it can be used to impersonate them, Ben Adida, Persona project lead at Mozilla, said Thursday via email. “There is, of course, no way around this.”
In this respect, Persona is not very different from password management applications that also rely on a master password to keep all of the user’s identities protected. However, Mozilla plans to implement some additional protection mechanisms to tackle this issue.
“For improved protection, we are working on two-factor authentication in future beta versions,” Adida said. Two-factor authentication requires something the user knows, like a password, and something the user has, like a hardware device or a mobile phone. Without having both of these elements, an attacker cannot gain access to an account.
Mozilla has also implemented a session protection mechanism in order to limit the security risks that can arise if a user’s laptop is stolen while he’s still logged into persona.org or if a user forgets to log out of persona.org after using a public computer.
“Users simply need to go change their password from any other computer, and any existing Persona sessions are then locked out and can no longer be used to authenticate the user,” Adida said.
“When a user enters their Persona password on a computer they haven’t used before, the session is initially just five minutes long,” he said. “Extending it requires typing in the password again, at which point we prompt the user to tell us whether this computer is theirs or is public.”
Persona still has a long way to go until it becomes a practical authentication alternative. First of all, Mozilla needs to convince website developers and important web services providers to adopt the system and implement it as an option into their websites. In order to facilitate this, a new and easier-to-use Persona API (application programming interface) was launched in August.
“If you are a developer, now is the time to try Persona out. Persona is an open source project and we gladly welcome input and collaboration from the broader community via our mailing list or our IRC channel,” the Mozilla Identity team said Thursday in a blog post.