Patent AU-2019203863-A1 (AU)
Title: Preventing misrepresentation of input data by participants in a secure multi-party computation
Inventor: LI LICHUN
IPC: G06F21/00
Filed: 2019-03-18
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 2019/101243 A2 
31 May 2019 (31.05.2019) W IPO I PCT 
(51) International Patent Classification: Alibaba Group Legal Department 5/F, Building 3, No.969 
Not classified West Wen Yi Road, Yuhang District, Hangzhou, Zhejiang 
(21) International Application Number: 311121 (CN). LIU, Zheng; Alibaba Group Legal Depart
PCT/CN2019/078516 ment 5/F, Building 3, No.969 West Wen Yi Road, 
Yuhang 
District, Hangzhou, Zhejiang 311121 (CN). YIN, Shan; 
(22) International Filing Date: Alibaba Group Legal Department 5/F, Building 3, No.969 
18 March 2019 (18.03.2019) West Wen Yi Road, Yuhang District, Hangzhou, Zhejiang 
(25) Filing Language: English 311121 (CN).  
(74) Agent: BEIJING BESTIPR INTELLECTUAL PROP
(26)PublicationLanguage: English ERTY LAW CORPORATION; Room 409, Tower B, Ka 
(71) Applicant: ALIBABA GROUP HOLDING LIMITED Wal Building, No. 9 Shangdi 3rd Street, Haidian District, 
[-/CN]; Fourth Floor, One Capital Place, P.O. Box 847, Beijing 100085 (CN).  
George Town, Grand Cayman (KY). (81) Designated States (unless otherwise indicated, for every 
(72) Inventors: LI, Lichun; Alibaba Group Legal Department kind ofnational protection available): AE, AG, AL, AM, 
5/F, Building 3, No.969 West Wen Yi Road, Yuhang Dis- AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, 
trict, Hangzhou, Zhejiang 311121 (CN). LIN, Wenzhen; CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, 
DZ, EC, EE, EG, ES, Fl, GB, GD, GE, GH, GM, GT, HN, 
(54) Title: PREVENTING MISREPRESENTATION OF INPUT DATA BY PARTICIPANTS INA SECURE MULTI-PARTY COM
PUTATION 
Secret Input Correspond Trusted 
Data + - - - - - - - - - - - - - - - -- - - - Input Data 
\ /\ / 
102a\ /102b 
110 
Network 
102c 102d 
100 FIG. 1 
(57) Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage 
media, for secure multi-party computation. One of the methods includes identifying a trusted input data item that is homomorphically 
i- encrypted; generating a message authentication code (MAC) key share; generating a MAC share associated with the trusted input data 
= item, wherein the MAC share is a random number; generating a ciphertext based on the trusted input data item, the MAC key share, 
and the MAC share; sending the ciphertext to the second computing device, wherein the second computing device uses the ciphertext 
as a component of a MAC share associated with the secret input data item; and after the multi-party computation is completed by the 
plurality of computing devices, verifying a result of the multi-party computation based at least in part on the MAC share associated 
CAwith the secret input data item.
W O 20 19/10 1243 A 2 ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 
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, Fl, FR, GB, GR, HR, HU, IE, 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).  
Published: 
- upon request of the applicant, before the expiration of the 
time limit referred to in Article 2](2)(a) 
- without international search report and to be republished 
upon receipt of that report (Rule 48.2(g))