Patent AU-2018348319-B2 (AU)
Title: Blockchain data protection using homomorphic encryption
Inventor: ZHANG WENBIN
IPC: H04L9/00
Filed: 2018-11-07
Granted: 2020-10-01
Abstract: INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) 
(19) World Intellectual Property 
(1) Organization11111111111111111111111I1111111111111i1111liiiii 
International Bureau (10) International Publication Number 
(43) International Publication Date W O 2019/072269 A2 
18 April 2019 (18.04.2019) W IPO I PCT 
(51) InternationalPatent Classification: (81) Designated States (unless otherwise indicated, for every 
Not classified kind ofnational protection available): AE, AG, AL, AM, 
AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, 
(21)InternationalApplicationNumber: CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, PCT/CN2018/114421 DZ, EC, EE, EG, ES, Fl, GB, GD, GE, GH, GM, GT, HN, 
(22) International Filing Date: HR, HU, ID, IL, IN, IR, IS, JO, JP, KE, KG, KH, KN, KP, 
07 November 2018 (07.11.2018) 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, 
(25)FilingOLanguage: English M, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, 
(26) Publication Language: English SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, 
(71) Applicant: ALIBABA GROUP HOLDING LIMITED TR, TT, TZ, UA, UG, US, UZ, VC, VN, 
ZA, ZM, ZW.  
[-/CN]; Fourth Floor, One Capital Place, P.O. Box 847, (84) Designated States (unless otherwise indicated, for every 
George Town, Grand Cayman (KY). kind of regional protection available): ARIPO (BW, GH, 
GM,RKE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, 
(72) Inventors: ZHANG, Wenbin; Alibaba Group Legal De- UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, 
partment, 5/F, Building 3, No. 969 West Wen Yi Road, TM), European(AL,AT, BE,BG, CH, CY, CZ, DE, DK, 
Yuhang District, Hangzhou, Zhejiang 311121 (CN). MA, EE,ES, FFR, GB,GR, HR, HU, , IS,IT, LT, LU, LV, 
Baoli; Alibaba Group Legal Department, 5/F, Building3 MC, MK, MT, NL, NO, PL,PT, RO, RS, SE,SI, SK, SM, 
No. 969 West Wen Yi Road, Yuhang District, Hangzhou, TR), OAPI (BF, BJ, CF,CG, CI, CM, GA, GN, GQ, GW, 
Zhejiang311121(CN). KM, ML, MR, NE, SN, TD, TG).  
(74) Agent: BEIJING BESTIPR INTELLECTUAL PROP
ERTY LAW CORPORATION; Room 409, Tower B, Ka 
Wal Building, No. 9 Shangdi 3rd Street, Haidian District, 
Beijing 100085 (CN).  
(54) Title: BLOCKCHAIN DATA PROTECTION USING HOMOMORPHIC ENCRYPTION 
(57) Abstract: Implementations of the present disclosure include receiving, 
300 by a consensus node from a first account, a digitally signed copy of a com
yf mitment value of a transaction amount, a second random number encrypted 
using a public key of the first account, a third random number encrypted using 
useroe 302 &oc;11, - 304 a public key of the second account, one or more range proofs, and a set of 
values generated based on one or more selected random numbers. The con
306 sensus node then verifies a digital signature corresponding to the digitally 
signed copy using a public key of the first account corresponding to a private 
A T elJG key used to generate the digital signature. It also updates the balance of the 
308 first account and a balance of the second account based on the amount of the 
Gsren:ra em rangescTs balance transfer if the first random number, the second random number, and 
310 the third random number are the same.  
Generatigaeofva e aone ormreseleced 
312 
Usin rVa[ekeyierneeAfoig i sgnaure 
- 314 
S ubTing a digally signed cpy wo a blockchain ne ork 
316 
318 
320 
(I Le' ern rn rsrra r r ..fn Ionrna n brer 
N 322 
FIG. 3 
CA
W O 2019/072269 A269|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 
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))