CAREER: Securing Active Information

保护活动信息当多方试图协作时，他们通常不得不牺牲其私有信息的机密性。安全多方计算和混淆等密码学原语旨在缓解这种情况。我们将许多这样的问题视为我们称之为活动信息的统一范式的一部分：系统中的各方可以访问系统中信息的规定操作，但仅此而已。该项目的第一个重点领域是安全多方计算，它允许互不信任的各方通过协议模拟共同信任的一方。我们确定并研究了在实践中有用的关键属性：“网络感知”解决了在现实复杂环境中出现的问题，而一类新的“上下文感知”特性对于将安全多方计算集成到更大的应用程序中至关重要。我们还通过将各种多方计算任务分类为复杂性类来深入了解它们的基本性质。这个项目的另一个重点是“安全活动对象”，与协议相比，它在使用上提供了更大的灵活性。我们研究了众所周知的（但很少被理解的）概念，如混淆，以及我们开发的新工具，如“远程启动混淆”和“主动加密”，以及匿名和不可链接等对应用程序很重要的功能。安全的活动对象也可以作为一个平台，将基于硬件的安全解决方案的研究集成到密码学理论中。开发的工具范围很广，从用于构造的低级代数技术到概念化安全定义的高级框架。为了将理论密码学的微妙概念带给当前和未来从业者的更广泛的受众，正在开发两个在线资源：(1)基于维基百科的教程/参考网站，(2)针对学生和非专业受众的博客。

Securing Active InformationAbstractWhen multiple parties attempt to collaborate, they often end up having tocompromise the confidentiality of their private information. Cryptographicprimitives like secure multiparty computation and obfuscation are aimed atmitigating this situation. We view many such problems as part of a unifyingparadigm that we call Active Information: various parties in a system can haveaccess to prescribed actions of the information in the system, but nothingmore.The first focus area of the project is secure multiparty computation, whichlets mutually distrusting parties emulate a commonly trusted party, by meansof a protocol. We identify and investigate crucial properties required forthis to be useful in practice: "network-awareness" addresses issues that arisein a realistically complex environment, and a new class of "context-awareness"features are vital in integrating secure multiparty computation into a largerapplication. We also derive insight into the fundamental nature of variousmultiparty computation tasks by classifying them into complexity classes.Another focus of this project is on "secure active objects" that offer farmore flexibility in their use, compared to protocols. We study well-known (butlittle understood) concepts like obfuscation, as well as new tools we developlike "remotely primed obfuscations," and "active encryptions," and alsofeatures like anonymity and unlinkability that are important for applications.Secure active objects also serve as a platform to integrate the study ofhardware-based security solutions into the theory of cryptography.The tools developed span a wide spectrum, ranging from low-level algebraictechniques used in constructions, to high-level frameworks for conceptualizingsecurity definitions.Towards bringing the subtle concepts from theoretical cryptography to abroader audience of current and future practitioners, two online resources arebeing developed: (1) a wiki-based tutorial/reference website, and (2) a blogaimed at students and a non-specialist audience.