US 12,316,611 B2
Enhanced security for existing public key infrastructure
Dakshita Khurana, Champaign, IL (US); and Brent Waters, Austin, TX (US)
Assigned to NTT Research, Inc., Sunnyvale, CA (US); and The Board of Trustees of the University of Illinois, Urbana, IL (US)
Appl. No. 18/040,215
Filed by NTT Research, Inc., Sunnyvale, CA (US)
PCT Filed Aug. 1, 2021, PCT No. PCT/US2021/044108
§ 371(c)(1), (2) Date Feb. 1, 2023,
PCT Pub. No. WO2022/031563, PCT Pub. Date Feb. 10, 2022.
Claims priority of provisional application 63/059,995, filed on Aug. 1, 2020.
Prior Publication US 2024/0267198 A1, Aug. 8, 2024
Int. Cl. H04L 9/40 (2022.01); H04L 9/08 (2006.01)
CPC H04L 63/0428 (2013.01) [H04L 9/0869 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for generating a chosen ciphertext attack (CCA) secure message using a chosen plaintext attack (CPA) encryption scheme, the method comprising:
receiving, by a computerized processor coupled to a computerized memory, a plaintext message for encryption;
receiving, by the computerized processor, an encryption algorithm, wherein the algorithm comprises computer-readable instructions that when executed are capable of producing a ciphertext that is CPA secure;
executing, by the computerized processor, a hinting pseudorandom generator on a cryptographically secure pseudorandom seed to generate a pseudorandom encoding of the seed, and computing a one-time pad encryption c of the plaintext message using the pseudorandom encoding;
generating, by the computerized processor, a set S of equivocal commitments having openings to each bit of the seed, wherein an equivocal commitment is an unkeyed encryption of the seed with usual equivocal properties;
executing, by the computerized processor, the encryption algorithm on the equivocal commitment openings and a selected part of the pseudorandom encoding to obtain a set of ciphertexts C0;
generating, by the computerized processor, a set of specific commitments C1 to the equivocal commitment openings and the selected part of the pseudorandom encoding, wherein the commitment is an unkeyed encryption;
outputting, by the computerized processor, public parameters of the hinting pseudorandom generator, the one-time pad encryption c, the set S of equivocal commitments, the set of ciphertexts C0, and the set of commitments C1 as a CCA secure ciphertext output; and
transmitting, by a network interface of the computerized processor, the CCA secure ciphertext output to a remote device over a network.