Updatable lossy trapdoor functions and its application in continuous leakage
Lossy trapdoor functions (LTFs) were firstly introduced by Peikert and Waters . Since their introduction, LTFs have found numerous applications. In this paper we focus on the LTFs in the continuous leakage. We introduce the new notion of updatable LTFs (ULTFs) and give its formal definition and security properties. Based on these, we extend the security model of the LTFs to continuous leakage. Under the DDH assumption and DCR assumption respectively, we show two explicit LTFs against continuous leakage in the standard model. We also show the performance of the proposed schemes compared with the known existing continuous leakage resilient LTFs.