Verifiable (t, n) threshold secret sharing scheme using ECC based signcryption

Abstract

In this paper, a secured (t, n) threshold secret sharing scheme has been proposed which prevents cheating from participants as well as from trusted dealer (TD) (which distributes shared secrets and reconstructs shared secret key). Here, a signcryption scheme based on elliptic curve cryptography (ECC) which incorporates both the digital signature and encryption scheme in a single logical step is used which helps to protect authenticity of the participants of the scheme and confidentiality of the secret shares being transferred through the network. The participants transfer their secret shares to the dealer when they require reconstruction of the secret key after acquiring confidence that the dealer is not compromised or captured. Before reconstruction of secret key (using t out of n secret shares), the dealer detects and identifies the dishonest participants (cheaters) assuming that more than t participants will submit their secret shares to the dealer. The dealer uses the concept of consistency and majority of secrets as proposed by Lein Harn et al.[17]. The proposed scheme helps to prevent cheating of dishonest participants, captured or compromised trusted dealer. It also reduces computational cost and communication overhead as the proposed scheme uses ECC based signcryption scheme. © 2010 Springer-Verlag Berlin Heidelberg.