CAREER: Anonymous and Robust Multi-Recipient Communication: Foundations and Applications

内容分发是密码技术的一个重要应用领域。现有的多接收者通信安全解决方案，如广播加密，主要集中在内容发起者的关注上。该项目从更广泛的角度解决这一问题，其中包括接收者的隐私问题，并开发内容分发的加密模型和协议，提供数据保密以外的保证。这项研究的结果将使解决云存储相关隐私问题的解决方案成为可能。在研究过程中开发的技术将刺激密码学和信息隐藏社区的研究人员，从而潜在地促进领域之间的合作。该项目有四个具体的研究目标：(1)设计接收者的密码结构-匿名广播加密，它同时提供传输保密性，为接收者提供匿名性，并享受与标准广播加密相当的性能；(2)探索接收者匿名性和密文模糊性之间的关系，其指的是给定的密文对多个解密者可能看起来是有效的；(3)制定广播隐写的概念，以使广播信道能够用作秘密通信的媒介；以及(4)研究协作远程存储等应用，即一组用户私下和不经意地访问云中的共享内容。

Content distribution is an important application domain for cryptographic techniques. Existing security solutions for multi recipient communication, like broadcast encryption, focus mostly on the concerns of the content originator. This project tackles the problem from a broader perspective that includes the privacy concerns of the recipients, and develops cryptographic models and protocols for content distribution that provide guarantees beyond the mere secrecy of the data. The outcomes of this research will enable solutions that address the privacy issues associated with cloud storage. The techniques developed in the course of the research will be stimulating for researchers across the cryptography and information-hiding communities, thus potentially fostering collaborations between the fields. The project has four specific research objectives: (1) the design of cryptographic constructions for receiver-anonymous broadcast encryption that at once provide transmission secrecy, afford anonymity to the receivers, and enjoy performance comparable to standard broadcast encryption; (2) the exploration of the relationship between receiver anonymity and ciphertext ambiguity, which refers to the possibility that a given ciphertext might appear valid to multiple decryptors; (3) the formulation of the concept of broadcast steganography to enable the use of a broadcast channel as a medium for covert communication; and (4) the investigation of applications like collaborative remote storage, whereby a group of users accesses shared content in the cloud privately and obliviously.