Extractable Witness Encryption for KZG Commitments and Efficient Laconic OT

ePrint Report: Extractable Witness Encryption for KZG Commitments and Efficient Laconic OT

Nils Fleischhacker, Mathias Hall-Andersen, Mark Simkin

We present a concretely efficient and simple extractable witness encryption scheme for KZG polynomial commitments.
It allows to encrypt a message towards a triple $(\mathsf{com}, \alpha, \beta)$, where $\mathsf{com}$ is a KZG commitment for some polynomial $f$.
Anyone with an opening for the commitment attesting $f(\alpha) = \beta$ can decrypt, but without knowledge of a valid opening the message is computationally hidden. …

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