SAP SE
Efficient distributed secret shuffle protocol for encrypted database entries using dependent shufflers

Abstract:

The present disclosure involves systems, software, and computer implemented methods for a efficient distributed secret shuffle protocol for encrypted database entries using dependent shufflers. Each of multiple clients provides an encrypted client-specific secret input value. A subset of clients are shuffling clients who participate with a service provider in a secret shuffling of the encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a client-specific rerandomized encrypted secret input value. As a result, the client-specific rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.