Patent SG-11201903553V-A (SG)
Title: Blockchain data protection using homomorphic encryption
Inventor: MA BAOLI
Filed: 2018-11-07
Abstract: WO 19/07 226 4 A2 (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (43) International Publication Date 18 April 2019 (18.04.2019) WIPO I PCT 11111111111111011111111111111110111110100111111111110111011111111111111111011110111111 (10) International Publication Number WO 2019/072264 A2 [302 User nocie G B'ockc [ Generating a commitnent value of a transaction amount based c a first random number, and encrypting, based on homomorphic encryption, a second random number using a public key of user node A, and a third random number using a public key of user node 308 Generating one or more range proofs 310 (51) International Patent Classification: Not classified (21) International Application Number: PCT/CN2018/114344 (22) International Filing Date: 07 November 2018 (07.11.2018) (25) Filing Language: English (26) Publication Language: English (71) Applicant: ALIBABA GROUP HOLDING LIMITED [—/CN]; Fourth Floor, One Capital Place, P.O. Box 847, George Town, Grand Cayman (KY). (72) Inventors: MA, Baoli; Alibaba Group Legal Department 5/ F, Building 3, No.969 West Wen Yi Road, Yuhang District, Hangzhou, Zhejiang 311121 (CN) ZHANG, Wenbin; Al- ibaba Group Legal Department 5/F, Building 3, No.969 West Wen Yi Road, Yuhang District, Hangzhou, Zhejiang 311121 (CN). (74) Agent: BEIJING BESTIPR INTELLECTUAL PROP- ERTY LAW CORPORATION; Room 409, Tower B, Ka Wah Building, No. 9 Shangdi 3rd Street, Haidian District, Beijing 100085 (CN). (81) Designated States (unless otherwise indicated, for every kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IR, IS, JO, JP, KE, KG, KH, KN, KP, KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (84) Designated States (unless otherwise indicated, for every kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, 1E, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, KM, ML, MR, NE, SN, TD, TG). (54) Title: BLOCKCHAIN DATA PROTECTION USING HOMOMORPHIC ENCRYPTION (57) : Implementations of the present disclosure include receiving, 300 from a first account, a digitally signed copy of a commitment value of a first amount of a transaction amount generated based on a first random number, the first amount of the balance transfer and the first random number encrypt- ed using a public key of the first account, a second amount of the balance transfer and a second random number encrypted using a public key of the 306 second account, and a set of values generated based on one or more selected random numbers. The first account determines if the first amount and the second amount are the same and if the first random number and the second random number are the same based on the set of values, and updates the bal- ance of the first account and a balance of the second account based on the first amount of the balance transfer. G eneratng a setofvalue; based on one or more selected modem numbers 312 Using a private key of user node A for digfta sgnature 314 S ubmiaing a digitally signed copy m a blockchain network 316 Verifying the digitalsignature 318 Verifying the one or more range proofs 320 Determining the firsira odor, number, the second random number and the third random number are the sure based onthe set of values 322 Updating account ba lances of user node A and user node B FIG.3 [Continued on next page] WO 2019/072264 A2 I 11111 IIIIIIII 0 DOI 11111 ME 0 III 1101 001 1101 11 111111111111111111111111111011110 II III Published: upon request of the applicant, before the expiration of the time limit referred to in Article 21(2)(a) without international search report and to be republished upon receipt of that report (Rule 48.2(g))