公开(公告)号：US20190132116A1

公开(公告)日：2019-05-02

申请号：US15795890

申请日：2017-10-27

Applicant: NXP B.V.

Inventor： Wilhelmus Petrus Adrianus Johannus MICHIELS ,  Marcel MEDWED ,  Jan HOOGERBRUGGE ,  Ventzislav NIKOV ,  Bruce MURRAY ,  Joppe Willem BOS

IPC: H04L9/06 ,  H04L9/14

Abstract: A method for implementing a pseudo-random function (PRF) using a white-box implementation of a cryptographic function in N rounds, including: receiving an input to the PRF; receiving a cryptographic key in a first round; encrypting, using the white-box implementation of the cryptographic function and the cryptographic key, an input message that is one of M possible input messages based upon a portion of the input to produce a first output; for each succeeding round: encrypting, using the white-box implementation of the cryptographic function and an ith cryptographic key, further input messages that are one of M possible input messages based upon a further portion of the input to produce an ith output, wherein the ith cryptographic key is the output from the preceding round, wherein the white-box implementation of the cryptographic function only produces a correct output for the M possible input messages and produces an incorrect output for input messages that are not one of the M possible input messages.