Excited to share our new paper! Inspired by the impact of lookup tables in programmable cryptography (ZKPs, FHE), we introduce lookup-table (LUT) evaluation over BGG+ encodings. We see this as an important step toward practical iO!

We’ll keep improving the efficiency of key-homomorphic encodings, an important step toward practical iO. Let’s make this new space of programmable cryptography practical!

Limitation: Our method is not yet practical. Under our parameter constraints, even at the maximum admissible B, the required depth of LUT evaluation for modular multiplication still exceeds 150 levels, so we couldn't find practical parameters meeting the correctness condition.

Application: a key-policy attribute-based encryption scheme (selectively secure under Ring-LWE) compatible with our LUT evaluation. Increasing B lowers decryption cost, at the expense of higher key-generation cost and larger decryption keys, which is an attractive trade-off.

Contribution: Our new LUT evaluation method reduces this overhead without bootstrapping by operating directly on base-B digit encodings (B>2) rather than on bits. This implements the nonlinear operations shown in the figure more efficiently than the Boolean-simulation baseline.

Historically, BGG+ encodings have been used mainly to encode bits, forcing nonlinear integer operations to be implemented via Boolean circuits with large overheads. Bootstrapping for BGG+ encodings can mitigate this in theory, but it itself relies on heavy nonlinear operations.

BGG+ encodings underpin many next-generation cryptographic primitives, including predicate encryption, reusable garbled circuits, and indistinguishability obfuscation (iO). They require simulating nonlinear integer operations (e.g., modular multiplication) over encodings.

In programmable cryptography, especially ZKPs and FHE, lookup-table (LUT) evaluation has driven dramatic efficiency gains in recent years. We've published a new paper introducing LUT evaluation over key-homomorphic encodings, specifically BGG+ encodings. https://t.co/4hSCmbxaUq

We would like to sincerely thank the developers of OpenFHE and openfhe-rs, open-source lattice and FHE libraries. We are also grateful to Prof. Yuriy Polyakov for his valuable advice on preimage sampling and his insightful feedback on optimizing our implementation.

video link: https://t.co/XFPU9DzO69 slide ilnk:

The video of the talk at the Obfuscation Workshop held by the Simons Institute is now available /link below

New article released: we explain iO from a new perspective, using familiar building blocks such as FHE and Functional Encryption Check out the full post here: https://t.co/iss9xoPxUQ

Details about the talk are available here: https://t.co/N5pS5mJmwl We’re grateful to the Simons Institute for this wonderful opportunity!

We’re excited to announce that @SoraSue77 will present a talk about Diamond iO on Tuesday, June 24, from 4:30 pm to 5:00 at the Obfuscation Workshop in Berkeley hosted by Simons Institute(@SimonsInstitute). (link below)

Enrico will give whiteboard session about iO and our recent work at ZuBerlin(@ZuBerlinCity) this Friday 12am

3/ The corresponding implementation had tagged as v1.5.0:

2/ The updated paper is available at https://t.co/GE2Hgj2wWY. It includes a cryptanalysis of the non-standard assumptions underlying Diamond iO—namely, all-product LWE and evasive LWE.

1/ We are excited to share that we have recently updated our paper and implementation with a significantly simplified construction. (eprint and github link below)

Hello, World: the first signs of practical iO Today, we’re excited to announce that we have successfully implemented Diamond iO and completed its end-to-end workflow Check out the full post here: https://t.co/Dbu2nROMhX

Pia will introduce iO and give a sneak peek into our early results! Don't miss it 💎