About InkblotPasswords
Passwords almost always suffer from one or more serious problems. Users have a difficult time remembering strong (high-entropy, hard to guess) passwords. Users handle this difficulty by recording their password somewhere insecure, by selecting a weak but memorable password, or by using the same password at multiple sites.
Inkblot passwords solve most of these problems by helping users create a secure, personal password that is easy to remember. The user is presented with a sequence of random inkblots. Each should remind the user of a word -- a butterfly or a pumpkin, for example. For each image, the user then types the first and last letters of the word that came to mind -- such as by for butterfly or pn for pumpkin.
A century of psychological literature indicates that inkblot associations are intimately personal, and our own user studies verify that users almost always describe the same inkblots quite differently. Such personalization leads to passwords with high entropy, that is, passwords that are difficult to attack by guessing, whether by knowing the target of the attack or by using a dictionary.
Furthermore, our studies indicate that people find their associations to be very memorable. When the user logs in, she is presented with the inkblots in sequence. Most users find the mental images they associate with the inkblots hard to forget. After typing her password several times, a user develops a "muscle memory" and can log in quickly without referring to the inkblot images.
Reusing the same password at many sites weakens passwords. If a careless site transmits or stores a password without adequate protection, the user's account on any site that shares the same password is also compromised. Nothing prevents a user from learning a strong password on InkblotPassword.com and then reusing it at other sites.
Users reuse passwords because it amortizes the effort of memorizing a strong password across perhaps dozens of sites. If we instead let a user sign on in one place for every site she uses (single sign-on), she can memorize just a single password, and yet only the password site must be implemented securely to protect the password.
The Open ID protocol is an open protocol specifically designed to enable single sign-on to Internet services. InkblotPassword.com is an OpenID server; with your InkblotPassword.com account you can log into any OpenID-enabled site.
InkblotPassword.com is a research project deployed by Microsoft Research. It is for demonstration and research purposes only. You are welcome to try it out, but we make absolutely no promise that our implementation will protect your password. Don't use your account here to protect any data you care about, from money to your reputation. We also make no promise that the site will continue running. Should the service prove successful, Microsoft may consider offering the service as a commercial product or service. For now, consider it an unreliable, insecure service run by a couple research coneheads in their spare time, and trust it accordingly.
Microsoft Research will study the usage patterns of users of this site, to help us evaluate the inkblot password scheme. We will have access to the passwords and lists of OpenID consumer sites accessed by users of InkblotPassword.com. We will do our best to preserve the privacy of users of the site. However, we will report on our studies, including aggregate or anonymized versions of the data we have collected.
This research service uses images, and hence is only effective for users with sight. We have imagined variations that use the same psychological principles via other senses, and we may deploy such a variation as the project develops.
You can learn more about the principles behind inkblot passwords in this Microsoft Research technical report: MSR-TR-2004-85
You can contact us at inkblots@microsoft.com.