Authentication of Naming and Identity on the Internet
By Chelsea Barabas, Neha Narula and Ethan Zuckerman:
"Identity and naming are key aspects of publishing online, because they are what enable people who want to read a user’s content to find it and verify that the content was really created by the user they intended to find, as opposed to someone pretending to be them. Verifiable identity is an important aspect of engaging with one another and consuming content online. The most prevalent way to handle identity management on the web today is by creating a new set of login credentials for each new service one wants to use. Users share, publish, and link their usernames across these services together to form a connected “identity”. Most websites have their own username/password based login systems. They verify that you are really “you”–the person who originally signed up with that username–by ensuring that you know a secret only that person should know, the associated password.
It has become increasingly popular for applications to outsource this functionality to large, reputable sites like Google and Facebook, so users can use their existing Google or Facebook credentials to login to many different applications. Using Facebook or Google for authentication makes it easier for a new user to experiment with a service, as they don’t have to go through the time consuming process of creating a new user identity.
However, as we discussed in the risks section, the overreliance on a single identity provider can have worrisome ripple effects. If a dominant identity provider disappeared or, perhaps more likely, if a user’s account were suspended or compromised, then the user would be locked out of all other sites that depend on those credentials for identity authentication. This could make it very challenging for users to 80 publish and consume content across the web.
Another technique for establishing identity online is public key cryptography, though this is rarely used. In this paradigm, a user has two important pieces of information -- a public key, which everyone knows, and a private key, which only the user knows, and never shares with anyone. The user can use her private key to decrypt messages encrypted with her public key, and to sign messages, by showing that she is the owner of the private key (without revealing what it is). For example, if Jane registers her public key at a well-known public key directory, like pgp.mit.edu, then anyone can verify that content she has signed was in fact created by her. It is nearly impossible for someone else to pretend to be Jane without compromising her private key, or the public key directory.
Though cryptographic keys can be generated independently and thus are entirely under the user’s control, putting identity firmly in their own hands, they are not a common way for users to authenticate on the web–perhaps because it’s a confusing model to users who are used to usernames and passwords, and there aren’t a lot of easy-to-use public key directories that enable users to find one another based on their cryptographic identity. However, many applications use public key cryptography under the hood, without direct user involvement, like encrypted messaging systems Signal and WhatsApp. Also, more applications are being developed to make public key cryptography easier to use, like keybase.io.
There are other forms of identity, naming, and user authentication that leverage domain names, or URLs, as the basis for a user controlled identity. DNS is an important protocol on the Internet used for registering and resolving domain names: it solves the problem of resolving a human-readable name (i.e. google.com) to a specific IP address, or server location (i.e. 220.127.116.11). Users register domain names via domain name registrar through an independent multi-stakeholder organization called the Internet 80 One of the examples we described in the first section involved someone losing access to multiple applications when she was banned from Facebook. Facebook Connect has become one of the most popular ways of logging into websites, and as such, if a user violates Facebook’s terms of service, he or she could lose access to many different sites.
Corporation of Assigned Names and Numbers (ICANN), formerly under the US Department of Commerce. So if Jane wants to establish her own online identity using DNS she can pay a domain registrar like GoDaddy to register JaneDoe.com, and then use that domain as her “home” on the web. For example, Jane might keep a blog, a list of updates, a picture gallery, and her biography at janedoe.com. Similarly, a publication or aggregator could register a domain name like toptechstories.net and publish articles; by having and sharing a human-readable domain name, it is much easier for users to find them.
There are some projects that aim to help users utilize their websites as a way of creating a user-owned identity and using that to authenticate with third party websites. Once a user obtains a domain name, she can use an open protocol, such as OpenID, IndieAuth, webID, or Mozilla Personas, to authenticate her identity to another application that accepts this form of credentialing. Although this model gives users a lot of autonomy and control over their own identity (a user can put anything they want on their own website, up to what is allowed by their hosting provider; and it isn’t too difficult to find alternative hosting providers), it has some weaknesses we must consider. Security is not an integral part of DNS’s design; it’s possible for people to spoof a domain name and redirect traffic to a different IP address. To overcome this challenge, most websites employ certificates, which are dispensed via a hierarchy of certificate authorities.
A certificate authority binds cryptographic public keys to a specific domain or identity (like a person or an organization) through a process of issuing certificates (this functionality is actually similar to what a public key directory might provide, through certificate authorities often go one step further and actually verify a relationship to a real-world identity). This process enables a user’s browser to verify that the website they are visiting belongs to the owner who has registered that domain, by validating the server’s certificate–when you see a green lock in the browser URL bar, this means the website has a valid certificate. There are different levels of certificate validation, ranging from domain validation, a relatively simple validation which is granted when the requestor can prove access to the domain, usually by email, to extended validation, in which the certificate authority does more real-world validation, like showing the domain really corresponds to the company or organization it implies. There are a few large certificate authorities, like Verisign, which serve as the roots of a hierarchical structure of certificate authorities.
Previously, websites had to purchase a signed certificate from a reputable certificate authority in order to provide secure connections and work well with modern browsers. In 2016 a new, free certificate authority was released: Let’s Encrypt. Let’s Encrypt is a free, automated, and open certificate authority, provided by the non-profit Internet Security Research Group. The project’s aim is to provide an easy-to-use, 82 automated way for any website to obtain valid certificates, supporting a more secure web. Both Chromium and Mozilla have named it as important to their plans to phase out non-secure HTTP. Let’s Encrypt only offers the lowest level of certificate validation, 8384 domain validation, but it can be set up in a completely automated way and provides a viable path for all websites to upgrade to the more secure HTTPS. A major goal of the project is to be as transparent as possible; Let’s Encrypt regularly publishes transparency reports and publicly logs all certificate change transactions.
The existing certificate authority system is far from perfect, and there are many calls to re-architect or replace it. Certificate authorities can get compromised and start issuing reputable certificates for disreputable servers. For example, in 2011, a Dutch certificate authority, Diginotar, was compromised and issued many fraudulent certificates for common domain names like google.com and facebook.com. This was used to snoop on the web traffic of over 300,000 users in Iran. In 2015 the certificate authority China Internet Network Information Center (CNNIC) was removed from the trusted certificate authority list in Google’s Chrome browser due to insecure practices. Also in 2015, Symantec got in trouble with Google for issuing unauthorized certificates for Google domains.
Without a system like certificate authorities putting appropriate security in place, users would not be able to trust the websites they visit, and might have their credentials stolen. As we discussed before, concentrating user credentials and authentication power in a few hands is troublesome for freedom in publishing–it is a way for mega-platforms to restrict users’ ability to participate in a trusted online publishing environment. But at the same time, expecting every user to manage their own security (and recover in the case of compromise) is also dangerous. In order for users to aggregate and disseminate their own content, we need an authenticated naming scheme that enables others to easily find trustworthy content. Creating an independent system for identity and naming, one that is easy to use and doesn’t suffer from the same limitations as public key directories or DNS and certificate authorities, might make it feasible for users to self-publish and push their content across different applications." (http://dci.mit.edu/assets/papers/decentralized_web.pdf)