Efficient and Provably Secure Pairing Free ID-Based Directed Signature Scheme

Abstract

Nowadays electronic communication is ubiquitous, irreplaceable; Digital signature plays an essential role in these secure communications. Digital signatures have expanded rapidly along with mathematical advances in lattices, pairings and elliptic curves. Due to their high efficiency and strong security properties, the elliptic curve cryptographic schemes remain the best option for many security goals. Pairing free signature schemes on elliptic curves is an emerging area of interest for efficient community. To deal with specific application scenarios, digital signature schemes have evolved into many variants. One of such variant is Directed signature scheme. A directed signature is a kind of signature where the verification ability is controlled by the signer. Here the validity of the signature can be verified by a designated verifier only and nobody knows anything about the verifier. Directed signature schemes are suitable for applications where message is sensitive to recipient; for example bill of tax and health. In this paper we propose an efficient and secure pairing free Identity (ID) based directed signature (IDBDS) scheme over elliptic curves. To the best of our knowledge, this is the first scheme in ID based setting addressing about directedness in pairing free environment. We prove its security using random oracle model under the assumption that the Elliptic Curve Discrete Logarithm Problem (ECDLP) is hard. We compare our scheme with well known existing schemes and efficiency analysis shows that our scheme is more efficient than all other related schemes.