Threshold secret sharing schemes are ideal to protect confidential
information. In this paper, we propose a novel distributed threshold
secret sharing scheme based on spherical coordinates. As four non-coplanar
points can determine a unique sphere, we design transformation algorithms to
generate secret as sphere center and mapping algorithms to convert
participants to be sphere surface points. An algorithm to generate shadow
secrets is proposed based on spherical coordinates. Verifiability and
proactivity secret sharing are considered during the procedures of generating
shadows and recovering secret and four or more participants could recover
secret in our scheme. Performance analysis proves that the proposed scheme
has relatively advantage in computation complexity, storage space and
communication amounts during distribution and reconstruction processes, and
it can tolerate collusion attacks and detect dishonest participants.