Fully Secure Functional Encryption without Obfuscation
Previously known functional encryption (FE) schemes for general circuits relied on indistinguishability obfuscation, which in
turn either relies on an exponential number of assumptions (basically, one per circuit), or a polynomial set of assumptions, but
with an exponential loss in the security reduction. Additionally these schemes are proved in an unrealistic selective security
model, where the adversary is forced to specify its target before seeing the public parameters. For these constructions, full
security can be obtained but at the cost of an exponential loss in the security reduction.
In this work, we overcome the above limitations and realize a fully secure functional encryption scheme without using indistinguishability
obfuscation. Specifically the security of our scheme relies only on the polynomial hardness of simple assumptions on multilinear maps.
*Join work with Sanjam Garg, Shai Halevi, and Craig Gentry
DC Area Crypto Day
Cryptography and Information Security Seminar at MIT
