SaTC: CORE: Medium: Collaborative: Theory and Practice of Cryptosystems Secure Against Subversion

密码学学科提供了全球使用的基本数字工具，以确保数据隐私和真实性。随着这些工具的广泛部署--通常隐形地嵌入到商业软件或硬件中--一种非常规但毁灭性的网络攻击已经出现。这些攻击涉及部署一个被巧妙地颠覆的加密工具版本，该工具看起来运行正常，但实际上是故意以一种只有颠覆者才知道的秘密方式降低安全性。这样的攻击可以由软件包的作者、硬件设备的制造商或有意干扰所部署的产品的第三方来执行。最近发生的这类备受瞩目的事件突显了与这些袭击有关的威胁。这个项目是对这种环境下的安全的全面研究，包括开发允许对安全进行严格推理的形式模型，设计和分析抵抗颠覆的新密码工具，以及明确建议加强广泛使用的现有密码工具。该项目分为三个主要主题。第一个重点是建立密码安全模型，该模型在经典密码模型的基础上进行扩展，以充分反映恶意颠覆攻击：通常，这些模型要求密码工具的设计与黑盒测试过程的规范明确地结合在一起，以便在受到颠覆攻击的情况下，组合可以保证安全性。第二项工作是开发在这些新模型中实现安全的基本密码原语，并应用这些原语作为构建块来构建更大的系统和协议，这些系统和协议在颠覆的情况下仍保持安全。最后，为了将这些理论工具转化为实践，该项目致力于重新构建现有的基础设施工具，如IPSec、SSH和TLS协议，以加强它们的抗颠覆能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The discipline of cryptography provides the basic digital tools used across the globe to ensure data privacy and authenticity. With the broad deployment of these tools--often invisibly embedded in commercial software or hardware--an unconventional but devastating type of cyberattacks have emerged. These attacks involve deploying a cleverly subverted version of a cryptographic tool that appears to function normally, but in fact deliberately reduces security in a covert way that is known only to the subverting party. Such an attack can be carried out by the author of a software package, the manufacturer of a hardware device, or a third party who has contrived to interfere with the deployed product. Recent high-profile incidents of this kind have highlighted the threat associated with these attacks. This project is a comprehensive study of security in this setting, including development of formal models that permit rigorous reasoning about security, design and analysis of new cryptographic tools that resist subversion, and explicit recommendations for hardening the existing cryptographic tools in widespread use.The project is organized into three main threads. The first focuses on establishing cryptographic security models that expand on classical cryptographic models to adequately reflect malicious subversion attacks: in general, these models call for the design of cryptographic tools to be explicitly coupled with specification of black-box testing procedures so that the combination can guarantee security despite subversion attacks. The second effort pursues development of fundamental cryptographic primitives that achieve security in these new models and application of these primitives as building blocks to construct larger systems and protocols that retain security despite subversion. Finally, to transition these theoretical tools to practice, the project undertakes a practical effort to re-architect existing infrastructural tools, such as the IPSec, SSH and TLS protocols, to harden them against subversion.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.