CryptoDB
Garbled Circuit Lookup Tables with Logarithmic Number of Ciphertexts
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| Conference: | EUROCRYPT 2024 |
| Abstract: | Garbled Circuit (GC) is a basic technique for practical secure computation. GC handles Boolean circuits; it consumes significant network bandwidth to transmit encoded gate truth tables, each of which scales with the computational security parameter $\kappa$. GC optimizations that reduce bandwidth consumption are valuable. It is natural to consider a generalization of Boolean two-input one-output gates (represented by $4$-row one-column lookup tables, LUTs) to arbitrary $N$-row $m$-column LUTs. Known techniques for this do not scale, with naive size-$O(Nm\kappa)$ garbled LUT being the most practical approach in many scenarios. Our novel garbling scheme -- logrow -- implements GC LUTs while sending only a logarithmic in $N$ number of ciphertexts! Specifically, let $n = \lceil \log_2 N \rceil$. We allow the GC parties to evaluate a LUT for $(n-1)\kappa + nm\kappa + Nm$ bits of communication. logrow is compatible with modern GC advances, e.g. half gates and free XOR. Our work improves state-of-the-art GC handling of several interesting applications, such as privacy-preserving machine learning, floating-point arithmetic, and DFA evaluation. |
BibTeX
@inproceedings{eurocrypt-2024-34005,
title={Garbled Circuit Lookup Tables with Logarithmic Number of Ciphertexts},
publisher={Springer-Verlag},
author={David Heath and Vladimir Kolesnikov and Lucien K. L. Ng},
year=2024
}