Policy-Controlled Signature from NTRU Lattice

Abstract

Policy-controlled signature (PCS) was introduced by Pairat Thorncharoensri et al. at ICICS 2009, and improved at Computer Standards & Interfaces 2017. In this type of digital signature, signer can sign a message with some policies. Any verifier who does not satisfies the policies cannot verify the message. They also extended the notion of policy-controlled signature, and called it "universal policy-controlled signature". In their extended notion, they improve the flexibility of the PCS scheme by allowing a third party to equip the signature with policy, rather than the signer. In this work, we use the recent techniques in lattice to construct policy- controlled based signature from NTRU lattice. In particular, we adapt Léo Ducas et al.`s encryption and signature protocol on lattice (ASIACRYPT 2014), and combine them with Pairat Thorncharoensri et al.`s work to satisfy the properties of policy-controlled signature. Our contribution is developing the first quantum- resistant schema based on the policy-controlled signature.