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