Research On Verifiable Secret Sharing Scheme

With the wide application of information technology and network, much attention has been given to how to ensure security of information. Encryption is generally used for information security and confidentiality. The core of encryption technology is key. Secret sharing is a way which could distribute, store and recover the secret key. It changes traditional pattern of managing information in which encryption and decryption is executed by single person. It has the abilities of scattering responsibility and preventing authority cheating. The confidentiality is greatly improved. Verifiable secret sharing is a kind of secret sharing which can prevent the dealer and participants from cheating. As a safe secret sharing, verifiable secret sharing schemes are widely used in many fields, such as distributed computing, e-commerce.To overcome the shortcomings that existing in verifiable secret sharing schemes with general access structure and tamper-resistant public parameters, an improved verifiable general secret sharing scheme and three novel verifiable secret sharing schemes have been successfully constructed.Firstly, an existing verifiable general secret sharing scheme is introduced and analyzed, and the fact that the scheme could not prevent participants from cheating is pointed out. Based on this scheme, an improved scheme which could prevent participants from cheating is proposed. Secondly, aiming at majority of previous verifiable self-selecting sub-key schemes on secret sharing are based on the access structure of threshold, based on bilinear pairing, a self-selecting sub-key scheme on verifiable general secret sharing is proposed. Thirdly, in view of majority of verifiable multi-secret sharing schemes with general access structure only could apply to a structure with multi-secret, through extending the existing schemes, a verifiable general multi-secret sharing scheme with multi-access structure is proposed. In this scheme, every access structure has their different multi-secret, and the secrets could be recovered in one time when all participants of any authorized subset provide their sub-shadow keys. Lastly, in consideration of the shortcomings that the verifiable secret sharing schemes protect public parameters from being falsified, a novel verifiable dynamic secret sharing scheme with tamper-resistant public parameters is proposed. All public parameters in this scheme can be verified by the participants.Besides, these schemes have the same merits that participant's secret sub-key selected by the participant himself and there is no safe channel between the dealer and participant. The validity, security and property of these schemes is analyzed in detail. The main contents are summarized and future research work is pointed out at the end of the thesis.