SMPC nodes in the Multichain network are designed to collectively perform computations while keeping the data private. This means that each node only knows a part of the overall data or key, and no single node has complete information. The core of SMPC functionality lies in distributed key generation. In this process, the private key needed for authorizing transactions is divided and distributed across multiple nodes - meaning that each node independently owns a fragment of the key. This approach ensures that the complete private key is never fully assembled in one location, aiming to make it nearly impossible for bad actors to reconstruct the key and compromise the network. When a transaction occurs, it requires authorization, which is where SMPC nodes come into play. Instead of a single signature from one complete key, the transaction is authorized through multiple signatures – each coming from a fragment of the key held by different SMPC nodes.