Web Password Recovery:A Necessary Evil?

Web password recovery, enabling a user who forgets their password to re-establish a shared secret with a website, is very widely implemented. However, use of such a fall-back system brings with it additional vulnerabilities to user authentication. This paper provides a framework within which such systems can be analysed systematically, and uses this to help gain a better understanding of how such systems are best implemented. To this end, a model for web password recovery is given, and existing techniques are documented and analysed within the context of this model. This leads naturally to a set of recommendations governing how such systems should be implemented to maximise security. A range of issues for further research are also highlighted.Comment: v2. Revised versio

An Owner-managed Indirect-Permission Social Authentication Method for Private Key Recovery

In this paper, we propose a very secure and reliable owner-self-managed private key recovery method. In recent years, Public Key Authentication (PKA) method has been identified as the most feasible online security solution. However, losing the private key also implies the risk of losing the ownership of the assets associated with the private key. For key protection, the commonly adopted something-you-x solutions require a new secret to protect the target secret and fall into a circular protection issue as the new secret has to be protected too. To resolve the circular protection issue and provide a truly secure and reliable solution, we propose separating the permission and possession of the private key. Then we create secret shares of the permission using the open public keys of selected trustees while having the owner possess the permission-encrypted private key. Then by applying the social authentication method, one may easily retrieve the permission to recover the private key. Our analysis shows that our proposed indirect-permission method is six orders of magnitude more secure and reliable tha

Systems and models for secure fallback authentication

Fallback authentication (FA) techniques such as security questions, Email resets, and SMS resets have significant security flaws that easily undermine the primary method of authentication. Security questions have been shown to be often guessable. Email resets assume a secure channel of communication and pose the threat of the avalanche effect; where one compromised email account can compromise a series of other accounts. SMS resets also assume a secure channel of communication and are vulnerable to attacks on telecommunications protocols. Additionally, all of these FA techniques are vulnerable to the known adversary. The known adversary is any individual with elevated knowledge of a potential victim, or elevated access to a potential victim's devices that uses these privileges with malicious intent, undermining the most commonly used FA techniques. An authentication system is only as strong as its weakest link; in many cases this is the FA technique used. As a result of that, we explore one new and one altered FA system: GeoPassHints a geographic authentication system paired with a secret note, as well as GeoSQ, an autobiographical authentication scheme that relies on location data to generate questions. We also propose three models to quantify the known adversary in order to establish an improved measurement tool for security research. We test GeoSQ and GeoPassHints for usability, security, and deployability through a user study with paired participants (n=34). We also evaluate the models for the purpose of measuring vulnerabilities to the known adversary by correlating the scores obtained in each model to the successful guesses that our participant pairs made