US 9,813,244 B1
Distributed proactive password-based secret sharing
Nikolaos Triandopoulos, Arlington, MA (US); and Yupeng Zhang, College Park, MD (US)
Assigned to EMC IP Holding Company LLC, Hopkinton, MA (US)
Filed by EMC IP Holding Company LLC, Hopkinton, MA (US)
Filed on Dec. 30, 2015, as Appl. No. 14/984,389.
Int. Cl. H04L 9/08 (2006.01); H04L 9/30 (2006.01); H04L 29/06 (2006.01)
CPC H04L 9/3093 (2013.01) [H04L 63/0428 (2013.01); H04L 2209/24 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
obtaining a difference between an updated value of a share and a prior value of said share for at least one fixed-share party, wherein said updated value comprises a fixed share that is one of a plurality of shares of a secret, wherein said plurality of shares are held by a plurality of parties;
substantially randomly selecting, by said at least one fixed-share party, a first correction polynomial employed by a polynomial-based secret sharing scheme such that at least one polynomial coefficient corresponding to said at least one fixed-share party is a value that depends on the difference, wherein at least one non-fixed-share party substantially randomly selects a second correction polynomial such that at least one corresponding polynomial coefficient corresponding to said at least one non-fixed-share party is approximately zero;
obtaining said at least one corresponding polynomial coefficient of said second correction polynomial from said at least one non-fixed-share party; and
updating said fixed share by combining said prior value of said share with said at least one corresponding polynomial coefficient of said first correction polynomial and said at least one corresponding polynomial coefficient of said second correction polynomial.