ARPA Chain (ARPA) is a blockchain-agnostic Layer 2 computation network that prioritizes confidentiality and security. It uses Secure Multi-Party Computation (SMPC) and secret-sharing technology to enable data sharing and computation between multiple parties while preserving confidentiality and computational accuracy. This enables a variety of use cases, including data markets, key management and anti-credit fraud mechanisms, making it a versatile and secure solution for decentralized applications.