Relational Self-Custody builds upon the foundational principles of digital and biological self-custody, where an individual exercises sole control over a private key, safeguarding their assets independently. In relational self-custody the control of assets transcends the individual and requires the consensus of multiple parties. Relational Self-Custody operates on the principle that certain assets are too valuable, too sensitive, or too critical to be entrusted to a single entity alone. This model introduces shared responsibility, enhanced security, and decentralized trust mechanisms.

At its core, Relational Self-Custody relies on a threshold scheme, where a specified number of signatures from a larger group of keyholders are required to authorize transactions. Commonly referred to as ”2-of-3” or ”3-of-5” multi-signature setups, these schemes ensure that no single party can unilaterally control or transfer the assets. Instead, a predetermined number of parties must collectively approve any action, creating a distributed form of asset management that is inherently more secure and resistant to compromise.

This model is particularly relevant in scenarios where high-value assets, sensitive information, or group interests are at stake. Whether in the context of family wealth management, corporate treasuries, or decentralized organizations, Relational Self-Custody ensures that decisions about asset movement and control are distributed across trusted parties, significantly reducing the risk of theft, misuse, or unilateral action. It introduces a layer of accountability, as each keyholder plays an integral role in the custody and protection of the asset, making it a critical model for entities with a vested interest in maintaining security and autonomy.

In this chapter, we will explore the technical structure behind Relational Self-Custody, focusing on its two primary types: multi-signature and Multi-Party Computation (MPC). Both approaches allow multiple entities to collectively secure assets, but they differ in their underlying mechanisms and use cases. We will examine the practical scenarios where each is applied, as well as the security benefits they provide. By exploring threshold schemes in multi-signature setups and the cryptographic processes behind MPC, we will gain a deeper understanding of how these models enable multiple parties to share responsibility for asset security, ensuring that no single point of failure exists in the custody process.