The Quest to Replace Passwords

Passwords are protectors of digital identity.

How can we better understand and evaluate the real-world use of different web authentication schemes?

An interactive version of Bonneau et al.'s S&P 2012 paper.

Why Passwords?

On the Internet, no one knows who you are until you establish your identity. This is authentication, and the oldest method is by providing a secret phrase upon sign-in that only you know, a password.

There have been decades of technological growth since the early Internet. The entire world's knowledge is now at our fingertips, we can communicate with friends and family worldwide, and social influencers reach audiences of millions. But passwords haven't changed. At the end of the day, every person from young to old, novice to expert, needs to remember passwords as a basic skill for using the Internet. Why can't we do better?

Challengers exist: for example, password managers reduce the number of different words that need to be memorized and possibly improve password quality. To name a few others, people use biometric authentication, one-time email links, and physical tokens.

However, every alternative approach has at least one downside. Password managers demand inconvenient backup codes, one-time links require email access, and physical tokens get lost.

The Comparison

Passwords and 35 password-replacement schemes are compared in the matrix below, based on a full gamut of 25 benefits. Colors represent properties that are better or worse than the row currently highlighted. Click on any row to select it as the base of comparison.

Full benefitAlmost benefitNo benefitYou are currently comparing to Web passwords.ImprovementRegressionPropertiesCategoriesSchemesMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Web passwordsMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Password managers FirefoxMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable LastPassMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Proxy URRSAMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable ImpostorMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Federated OpenIDMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Microsoft PassportMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Facebook ConnectMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable BrowserIDMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable OTP over emailMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Graphical PCCPMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable PassGoMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Cognitive GrIDsure (original)Memorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable WeinshallMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Hopper BlumMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Word AssociationMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Paper tokens OTPWMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable S/KEYMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable PIN+TANMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Visual crypto PassWindowMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Hardware tokens RSA SecurIDMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable YubikeyMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable IronkeyMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable CAP readerMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable PicoMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Phone-based PhoolproofMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable CrontoMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable MP-AuthMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable OTP over SMSMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Google 2-StepMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Biometric FingerprintMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable IrisMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable VoiceMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Recovery Personal knowledgeMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Preference-basedMemorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable Social re-auth.Memorywise effortlessScalable for usersNothing to carryPhysically effortlessEasy to learnEfficient to useInfrequent errorsEasy recovery from lossAccessibleNegligible cost per userServer compatibleBrowser compatibleMatureNon-proprietaryResilient to physical observationResilient to targeted impersonationResilient to throttled guessingResilient to unthrottled guessingResilient to internal observationResilient to leaks from other verifiersResilient to phishingResilient to theftNo trusted third partyRequiring explicit consentUnlinkable

How to Read This

Each row of the table consists of a single authentication scheme that aims to replace or supplement passwords. They are grouped into broad categories. The authors of the source paper, as domain experts within their fields, qualitatively evaluate each of the properties that these schemes offer the end user, and their 25 criteria are shown in the columns of the table.

Note that the benefits of each scheme cannot simply be added up numerically, as some matter more than others contextually. As a qualitative evaluation, it has no direct numeric counterpart.

What next? Well, there's no one true solution to all of our authentication concerns. At least, the next time someone sings the praises of their favorite password replacement, you can link them here and give them far more information about benefits and drawbacks than they ever wanted. 😄

Made by Eric Zhang (@ekzhang1).