Design and optimisation of multi-party secure computing protocols supporting dynamic participant switching

Most existing SMPC protocols assume static participants, unsuitable for dynamic scenarios where participant numbers and identities change.This paper proposes an SMPC protocol enabling dynamic participant switching, introducing a dynamically joinable model with variable committee sizes per round and supporting arbitrary member counts.It uses secret sharing to transfer computations between participants without revealing intermediates and consolidates all validations into a dedicated phase to reduce communication complexity.Experiments with seven-member committees show its communication costs (for 10,000-10,000,000 data entries) and computational overheads (for 10,000,000 entries) outperform existing protocols.A platform based on Spring Boot and MyBatis, integrating libscapi for core crypto operations, is developed with optimised architecture and visualisation tools.The protocol offers efficient, secure solutions for data sharing and collaboration, with significant theoretical and practical value.