Secure multi-party computation (MPC) is a cryptographic protocol that lets several parties jointly compute a result while keeping each party’s inputs private. Instead of sending raw data to one trusted server, the parties split the work into coordinated protocol messages so that no participant learns more than the final output permits.
MPC matters in cyber security because it reduces the need to expose sensitive data to a single operator, cloud tenant, or analytics platform. It is used for privacy-preserving collaboration, regulated data sharing, distributed key management, and secure AI workflows where confidentiality must survive processing, not just storage. In defense, MPC can help organizations compute on data sets without centralizing them. In attacks, adversaries may try to disrupt MPC with malformed inputs, traffic analysis, or implementation flaws that leak metadata, timing, or partial values. The security of MPC depends on strong protocol design, honest majority or suitable trust assumptions, and correct implementation.