IACR News item: 25 December 2022
Pascal Lafourcade, Gael Marcadet, Léo Robert
ePrint Report
The verification of computations performed by an untrusted server
is a cornerstone for delegated computations, especially in multi-
clients setting where inputs are provided by different parties. As-
suming a common secret between clients, a garbled circuit offers the
attractive property to ensure the correctness of a result computed
by the untrusted server while keeping the input and the function
private. Yet, this verification can be guaranteed only once.
Based on the notion of multi-key homomorphic encryption (MKHE),
we propose RMC-PVC a multi-client verifiable computation proto-
col, able to verify the correctness of computations performed by an
untrusted server for inputs (encoded for a garbled circuit) provided
by multiple clients. Thanks to MKHE, the garbled circuit is reusable
an arbitrary number of times. In addition, each client can verify the
computation by its own. Compared to a single-key FHE scheme,
the MKHE usage in RMC-PVC allows to reduce the workload of
the server and thus the response delay for the client. It also enforce
the privacy of inputs, which are provided by different clients.
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