Periodic Reporting for period 2 - REACT (Realizable Advanced Cryptography)
Reporting period: 2019-04-01 to 2020-09-30
State of the art research suggests that new advanced cryptographic primitives can mitigate this tension. These include computing on encrypted data via fully homomorphic encryption, fine grained access control to encrypted data via attribute based encryption, and most recently general purpose program obfuscation, which on paper can solve many of cryptography's long standing problems. However, these primitives are largely either too complicated or not sufficiently founded to be considered for real world applications.
The goal of project REACT is to address and remove the barriers that stand between advanced cryptographic primitives and reality. Past research experience showed that orders-of-magnitude improvement in efficiency and security requires foundational theoretical study. Progress in this direction should both allow for future realistic implementation of these primitives, which can bring us closer to a society where utility does not come at the expense of privacy, as well as contribute to basic cryptographic study by developing techniques and opening new avenues for future research.
The project has the following objectives: (i) Studying the computational complexity of underlying hardness assumptions, in order to have a better understanding of the level of security we can expect of proposed primitives. (ii) Simplifying and extending the LWE/trapdoor paradigm that underlies many of the new primitives. (iii) Constructing cryptographic graded encoding schemes and obfuscators.
Our concrete achievements include:
- Better understanding of the applicability of lattice cryptography in the context of quantum computing and quantum protocols. Identifying this area as a major vector for progress towards a more complete understanding of advanced cryptography on the one hand, and opening new avenues in quantum computing on the other.
- Establishing the hardness of lattice problems, and related problems such as decoding random linear codes, in relations to well-studied quantum and classical computational problems.
- Improved methods for obfuscation and related primitives (such as witness encryption and constrained pseudorandom functions).
- Novel methods for construction of lattice-based cryptographic primitives.
Our work was presented in major venues in the field of cryptography and theoretical computer science at large. Dissemination efforts include participating and organizing in conferences, workshops, seminars, and cross visits with collaborators around the world.