Changeable Threshold Signature Scheme Based on Lattice Theory

The current changeable threshold signature schemes are generally based on RSA or ECC algorithm. They often have shortcomings of the large amount of calculation, need the dealer to participate in when adjusting the threshold etc. This paper introduced the related concepts and theories of lattice, proposed a novel changeable threshold signature scheme and analyzed the essential security, it based on the changeable threshold Shamir secret sharing scheme and NTRUSign signature algorithm. The scheme has the following properties: It is mainly based on polynomial multiplication and integer coefficient modular arithmetic and needn´t introduce exponential operation; It needn´t redistribute the subsecret and modify the group public key when changing threshold; The scheme guarantees threshold security, robustness and unforgeability.