SaTC: CORE: Medium: Collaborative: New Frontiers in Encryption Systems

加密是将数据编码为密文的过程，只有预期的接收者才能解码和学习数据。这个项目推动了加密技术的发展。该项目的创新之处在于构建具有先进功能的加密系统，这些系统在标准假设下具有可证明的安全性。这些功能包括跟踪泄露机密信息的恶意用户的能力，以及仅在需要了解的基础上向用户发布选定信息的能力。该项目的影响是开发新一代的加密系统，这些系统是建立在可靠和经过测试的数学基础之上的。(1)选择密文安全。选择密文安全性（IND-CCA）可以说是传统加密系统以及具有高级功能的加密系统的正确安全概念。研究人员调查了将具有选定明文（IND-CPA）安全性的系统转换为IND-CCA安全性的通用方法和新工具。 (2)加密系统中的追踪。 叛逆者追踪是确定广播系统中解码器盒的来源的问题。 研究人员探索具有挑战性的新问题，包括：对于任何常数c，获得具有N^{1/c}大小的密文的跟踪和广播系统，实现相同参数的公共可追溯性，并使用跟踪技术作为证明自适应安全性的工具。(3)基于错误学习（LWE）假设的系统新前沿。 基于LWE的密码学是一个令人兴奋的途径，可以从一个经过充分研究的假设中产生新的功能。 研究人员将追求建立基于LWE的密码学的雄心勃勃的目标。 其中包括混淆伪随机函数及其应用的新概念，以及从LWE构建见证加密的程序，该程序的中间目标是为位修复功能构建受约束的伪随机函数。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响评审标准进行评估，被认为值得支持。

Encryption is the process of encoding data into a ciphertext such that only the intended recipient can decode and learn the data. This project pushes the frontiers of what is achievable for encryption. The project's novelties are building encryption systems with advanced capabilities that have provable security under standard assumptions. These include the capability to trace malicious users who leak confidential information as well as the ability to only release select pieces of information to users on a need to know basis. The project's impacts are the development of a new generation of encryption systems that are built from reliable and tested mathematical underpinnings.The project consists of three primary thrusts. (1) Chosen ciphertext security. Chosen ciphertext security (IND-CCA) is arguably the right notion of security both for traditional encryption systems as well as ones with advanced functionality. The investigators investigate generic methods and new tools for converting systems with chosen plaintext (IND-CPA) security into IND-CCA ones. (2) Tracing in encryption systems. Traitor tracing is the problem of determining the source of a decoder box in a broadcast system. The investigators explore challenging new problems including: getting trace and broadcast systems with N^{1/c} sized ciphertexts for any constant c, achieving public traceability for the same parameters and using tracing techniques as a tool for proving adaptive security. (3) New frontiers in systems based on the Learning with Errors (LWE) assumption. LWE-based cryptography is an exciting avenue for producing new functionality from a well-studied assumption. The investigators will pursue ambitious goals for building LWE-based cryptography. These include a new concept of obfuscating pseudorandom functionalities and its applications as well as a program for constructing witness encryption from LWE beginning with an intermediate goal of building constrained pseudo-random functions for the bit fixing functionality.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.