ImPAKT: Real-World Implementation and Human-Centered Design of PAKE Technologies

互联网已经成为现代社会的基础。我们每天都在使用电子邮件、电子银行、电子政务、电子商务、社交媒体和云存储等服务。这些服务需要安全地建立用户身份并与他们安全通信的机制。意外甚至恶意的错误身份验证会带来经济损失、信息泄露和身份盗用等安全威胁。尽管基于密码的身份验证经常被宣布为“死亡”，但在需要更高安全保证时，基于密码的身份验证仍然是用户身份验证的主要形式，无论是作为独立的还是多因素身份验证方案的一部分。尽管基于密码的身份验证存在一些安全问题，但这一点仍然存在。已经开发和部署了许多工具来解决这些问题：密码强度计，以帮助用户选择更强的密码，主动检查泄露的密码，以防止密码重复使用和泄露的凭据造成的伤害，基于风险的身份验证，以检测恶意登录，等等。然而，即使在最先进的安全机制存在的情况下，网络钓鱼攻击仍然是最严重的威胁。密码认证密钥交换（PAKE）协议提供了强大的保护，防止网络钓鱼攻击，并带来了其他几个优点，如建立前向和后向安全的加密会话密钥。ImPAKT的主要目标是改进互联网上基于密码的身份验证技术。这将通过全面了解PAKE协议及其在实践中的实现来完成。该项目将通过调查和访谈从从业者那里获得广泛的投入，以更好地了解拦截器在实践中的确切性质和影响，以及PAKE协议的替代（非钓鱼）安全目标的重要性，例如服务提供商永远不会看到明文密码。我们将在PAKE协议的一组新的技术要求中综合这一点（例如启用强度估计，处理错别字或风险评估），并为这些设置提供加密安全模型。该项目将通过一系列的用户研究，详细研究用户如何与PAKE协议进行交互，以及如何设计协议和接口，以方便使用和防止网络钓鱼攻击。最后，该项目将构建新的协议来支持新的需求和可用性约束，并提供高效和现成的开源实现，以及验证这些协议的可用性。

The Internet has become the foundation of modern society. On a daily basis, we consume services such as e-mail, ebanking, e-government, e-commerce, social media, and cloud storage. These services require mechanisms to securely establish the identity of the user and communicate securely with them. Accidental or even malicious mis-authentication runs the risk of security threats ranging from economic loss, information leaks to identity theft.Despite being declared "dead" on a regular basis, password-based authentication is still the predominant form of user authentication either as stand-alone or part of multi-factor authentication schemes when higher security guarantees are required. This is despite the fact that password-based authentication suffers from several security problems. A number of tools have been developed and deployed to address these problems: password strength meters to help users choosing stronger passwords, proactively checking leaked passwords to prevent harm from password re-use and leaked credentials, risk-based authentication to detect malicious sign-ins, and more. However, phishing attacks still present the most significant threat, even in the presence of state-of-the-art security mechanisms. Password-Authenticated Key Exchange (PAKE) protocols offer strong protection against phishing attacks and bring several other advantages such as the establishment of forward and backward secure cryptographic session keys. However, their use in practice has been very limited.The main goal of ImPAKT is to improve the state of the art of password-based authentication on the Internet. This will be done by taking a holistic view of PAKE protocols and their implementations in practice. The project will take extensive input from practitioners via surveys and interviews to better understand the exact nature and impact of blockers in practice, as well as the importance of alternative (non-phishing) security goals for PAKE protocols such as service providers never seeing plaintext passwords. We will synthesize this in a new set of technical requirements for PAKE protocols (such as enabling strength estimates, handling typos, or risk assessment) and provide cryptographic security models for these settings. The project will study in detail, through a series of user studies, how users are interacting with PAKE protocols and how protocols, as well as interfaces, need to be designed to facilitate use and prevent phishing attacks. Finally, the project will construct novel protocols to support the new requirements and usability constraints, and provide efficient and ready to use implementations as open-source, as well as, validating the usability of these.