The Quest to Replace Paswords

1. The Quest to Replace Paswords By Joseph Bonneau, Cormac Herley, Paul C. van Oorschot, Frank Stajano

2. Introduction • At present, the PASSWORDS are playing dominant role as End-User authentication. • The issues commonly encountered are • Though web technology is evolving, the passwords stubbornly survive and reproduce with each web site. • Have server security issues. • Openly hated because of inconvenience of usage. • To address the issues of passwords, many security researchers came up with alternative authentication schemes. • Several authentication schemes are invented as replacement to passwords. To name a few categories • Password management software • Federal login protocols • Graphical Password schemes • Cognitive authentication schemes • Hardware tokens. • One-time passwords • Phone aided schemes etc. • To evaluate all these schemes, a standard benchmark and framework is introduced with 25 properties for analyzing wide spectrum of benefits they offer, when compared to text passwords. • To rate the pros and cons of each scheme, this framework is used extensively on 35 password replacement schemes • Main focus in the rating process is user authentication on the web, specifically from client devices like PCs to remote verifiers. That means, human-to-machine authentication, but not machine-to-machine.

3. Benefits • The benefits of the each scheme to be considered are placed under three categories Usability Benefits UDS Deployability Benefits Security Benefits • Usability Benefits (Total 8) • Memorywise Effortless • Quasi-Memorywise effortless (if to remember one secret for every thing) • Scalable for users • Using the same scheme for hundreds of accounts does not increase burden on the user. • from user’s cognitive load perspective , but not system resource perspective • Nothing-to-Carry ( no need to carry a physical object including piece of paper) • Quasi-Nothing-to-Carry ( for devices that are carried every where all the time. Eg. mobile phone) • Physically-Effortless (no physical user effort beyond, say, pressing a button) • Quasi-Physically-Effortless ( if the user’s effort is limited to speaking) • Easy-to-Learn (easy to learn and easy to recall with out too much trouble) • Efficient-to-Use (time spent for each authorization is to be short) • Infrequent-Errors (reliable and no regular rejections for genuine users) • Easy-Recovery-from-Loss (Low latency before restored, Low user inconvenience , Assurance for recovery) • Deployability Benefits (Total 4) • Accessibile • not prevented by disabilities or other physical conditions) • Negligible-Cost-per_User ( summation of cost per user, costs at prover’s end and verifier’s end is negligible) • Server-Compatible (text-based passwords should be compatible at the verifier’s end) • Browser-Compatible( not to change the client and machine with an up-to-date, standard compliant web browser with no additional plugins) • Quasi-Browser-Compatible ( if they rely on non-standard but very common plugins, e.g., Flash)

4. Benefits (continued..) • Mature ( this is decided based on the following factors..) • implemented and deployed on large scale • Undergone user testing • Whether standards community has published related documents • Whether any open source project is implementing this scheme • Whether any third part has adopted the scheme • Amount of literature on this scheme. • Non-Proprietary • no royalties to be paid for any purpose usage, • published openly and not protected by patents or trade secrets • Security Benefits (Total 11) • Resilient-to-Physical-Observation • An attacker can not impersonate a user after observing the authentication one or more times. • Attacks include shoulder surfing, filming the keyboard, recording keystroke sounds or thermal imaging of keypad. • Quasi-Resilient-to-Physical-Observation • If the scheme can be broken by observing more than, say, 10-20 times. • Resilient-to-Targeted-Impersonation • Can not impersonate a specific user by exploiting knowledge of personal details(birth date, names of relatives etc.) • Resilient-to-Throttled-Guessing • An attacker whose rate of guessing is constrained by the verifier. • Throttling mechanism can be enforced by an online server, a tamper-resistant chip. • Resilient-to-Unthrottled-Guessing • An attacker whose guessing rate is constrained only by available computing resources. • Resilient-to-Internal-Observation • Can not impersonate a user by intercepting the user’s input from inside the user’s device(e.g., by key logging malware) • Cant not impersonate by eavesdropping on the clear text communication between prover and verifier(assumig attacker can also defeat TLS if it is used, perhaps through the CA)

5. Benefits (continued..) • Hardware devices dedicated exclusively to the scheme can be made malware-free, though personal computers and mobile phones may contain malware. • Quasi-Resilient-to-Internal-Observation • If the scheme could be broken by intercepting or eavesdropping by more than, say, 10-20 times. • Resilient-to-Leaks-from-Other-Verifiers • Nothing that a verifier could possibly leak can help an attacker impersonate the user to another verifier. • Resilient-to-Phishing • An attacker who simulates a valid verifier (including by DNS manipulation) cannot collect credentials that can later be user to impersonate the user to the actual verifier. • Resilient-to-Theft • If the scheme uses a physical object for authentication, the object can not be used by another person who gains possession of it. • Quasi-Resilient-to-Theft • If the protection is achieved with the modest strength of a PIN. • No-Trusted-Third-Party • The scheme does not rely on a trusted third party(other than the prover and the verifier) • Requiring-Explicit-Consent • The authentication process can not be started with out the explicit consent of the user. • This is both a security and a privacy feature. • Unlinkable • This is privacy feature. • Colluding verifiers can not determine, from the authenticator alone, whether the same user is authenticating both.

6. Evaluation of Schemes with ratings • Evaluation of Legacy Passwords • Highly scores in Deployability. • Evaluation of Encrypted Password Managers : Mozialla Firefox • Highly scores in Deployability.

7. Evaluation of Schemes with ratings • Evaluation of Proxy Based : URRSA • Evaluation of Federated Singel Sign-On : OpenID • Favorable from deployment point of view.

8. Evaluation of Schemes with ratings • Evaluation of Graphical Passwords : Persuasive Cued Clickpoints (PCCP) • Evaluation of Cognitive Authentication : GrIDsure

9. Evaluation of Schemes with ratings • Evaluation of Paper Tokens : OTPW • Evaluation of Hardware tokens : RSA Secure ID

10. Evaluation of Schemes with ratings • Evaluation of Mobile Phone-based : Phoolproof • Evaluation of Biometrics : Fingerprint recognition

11. Comparisons of Various Schemes

12. Comparisons of Various Schemes(Continued)

13. Conclusion • No Scheme that is examined is perfect- or even comes close to perfect scores. • The incumbent (traditional passwords) achieves all benefits on deployability. • Not a single scheme is dominant over passwords.