Alcatel Lucent

Ranjit Kumaresan

Vladimir Y Kolesnikov

Abdullatif Shikfa

Server-assisted secure function evaluation (SFE) is performed with input consistency verification for two parties that want to evaluate a function. The server computes a garbled circuit corresponding to the function. A predefined bit of the 0-secret of wire i in the garbled circuit is set to a random bit band a predefined bit of the 1-secret of wire i in the garbled circuit is set tob. The server communicates with each party using an Oblivious Transfer (OT) to provide encrypted versions of the respective inputs of each party. Each party receives the encrypted wire secret of the other party and the garbled circuit for computation of a respective output and stores the predefined bit of a wire of interest of the other party. A given party can verify input consistency by the other party over at least two executions by comparing the values stored by the given party for the at least two executions with corresponding values obtained from the server.

Input consistency verification for server assisted secure function evaluation

Methods and apparatus are provided for secure function evaluation for a covert client and a semi-honest server using string selection oblivious transfer. An information-theoretic version of a garbled circuit C is sliced into a sequence of shallow circuits C, . . . C, that are evaluated. Consider any wire wof C that is an output wire of C, and is an input wire of C. When a slice Cis evaluated, C's 1-bit wire key for wis computed by the evaluator, and then used, via string selection oblivious transfer (SOT), to obtain the wire key for the corresponding input wire of C. This process repeats until C's output wire keys are computed by the evaluator. The 1-bit wire keys of the output wires of the slice are randomly assigned to wire values.

Secure function evaluation for a covert client and a semi-honest server using string selection oblivious transfer

Methods and apparatus are provided for secure function evaluation between a semi-honest client and a semi-honest server using an information-theoretic version of garbled circuits (GC). An information-theoretic version of a garbled circuit C is sliced into a sequence of shallow circuits C, . . . C, that are evaluated. Consider any wire wof C that is an output wire of C, and is an input wire of C. When a slice Cis evaluated, C's 1-bit wire key for wis computed by the evaluator, and then used, via oblivious transfer (OT), to obtain the wire key for the corresponding input wire of C. This process repeats until C's output wire keys are computed by the evaluator. The 1-bit wire keys of the output wires of the slice are randomly assigned to wire values.

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College Park, MD, United States of America

Ranjit Kumaresan