Open AccessComputational SS and conversion protocols in both active and passive settings
Author(s) -
Kikuchi Ryo,
Ikarashi Dai,
Chida Koji,
Hamada Koki,
Ogata Wakaha
Publication year - 2017
Publication title -
iet information security
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.308
H-Index - 34
eISSN - 1751-8717
pISSN - 1751-8709
DOI - 10.1049/iet-ifs.2016.0276
Subject(s) - computer science , protocol (science) , code (set theory) , block (permutation group theory) , computation , secure multi party computation , computational complexity theory , distributed computing , algorithm , mathematics , programming language , geometry , set (abstract data type) , pathology , medicine , alternative medicine
Secret sharing (SS) has been extensively studied as both a means of secure data storage and a fundamental building block for multiparty computation (MPC). For these purposes, code‐efficiency and MPC‐suitability are required for SS but they are incomparable. Recently, a computational SS and a conversion protocol were proposed. The computational SS is code‐efficient and the conversion protocol converts shares of the computational (code‐efficient) SS into those of an MPC‐suitable SS, and it can be applied to reduce the amount of data storage while maintaining extendibility to MPC. However, this protocol is one‐way: one cannot convert the share of MPC output value. In addition, it is only passively secure. The authors propose three protocols and a new computational SS. The first protocol is the inverse of the existing protocol, that is, it converts an MPC‐suitable SS to the existing SS. The other two protocols are actively secure conversion protocols that convert shares between the new SS and an MPC‐suitable SS. The new computational SS is code‐efficient when the number of parties is small, so these two protocols are for converting between the code‐efficient SS and an MPC‐suitable SS. These two conversion protocols are actively secure in the honest majority.