Standards and Cryptography

# BDOZ MPC Protocol

Corex Network currently executes on the BDOZ MPC protocol, a protocol enables secure multiparty computation in environments with a dishonest majority. It uses additively homomorphic encryption and pairwise Message Authentication Codes (MACs) for security. The protocol emphasizes efficient preprocessing, which handles computationally intensive tasks before the main computation to enhance performance. BDOZ is designed to offer active security, ensuring safe execution even if some parties attempt to act maliciously.

• MPC protocols vary in their security models and cryptographic assumptions. In terms of security, protocols can assume an honest majority, where more than half the participants are trustworthy, or a dishonest majority, where even if most collude, they can't compromise the protocol. Protocols may also rely on computational or information-theoretic security. Advanced protocols like BDOZ use a preprocessing model, allowing resource-intensive tasks to be handled offline, making real-time computation faster by consuming pre-generated data during lighter network loads.

• Corex Network data encryption is managed based on the Joint Computing Environments level, where each joint computing environment is assigned an encryption scheme by the processing client during its creation. If encryption isn’t needed for a specific use case, it can be omitted, otherwise a designated encryption key secures the data processed within the joint computing environment.

  Additionally, the same encryption scheme can be shared under the same processing client, offering slight cost savings by avoiding the need for multiple, unique encryption schemes for each environment.