MPC wallet key share enhancements

Summary of the October 2025 enhancements to key share management and security in MPC Wallets.

To enhance the usability and security of MPC Wallets, the configuration, interface, and security mechanisms for key shares were optimized in October 2025. The updates are described below.

Across all modes, Cobo does not control or use client key shares. Any key share stored within Cobo’s multi-cloud infrastructure is encrypted and stored on the client’s behalf, and remains under the client’s control.

1. Optimization of key share concepts and configuration

Standard mode

Naming optimization

The concept of key share holder groups has been simplified to keys, and all groups have been renamed as follows:

Original Name	New Name
Main Group	Main Key
Signing Group	Signing Key
Recovery Group	Recovery Key

The structure and meaning of the keys remain unchanged. For example, the process of creating a Main Key is the same as the previous process of creating a Main Group: the client generates one key share, and the other key share is generated within and stored encrypted in Cobo’s multi-cloud infrastructure on the client’s behalf. Together, the two key shares form a complete private key.

UI/UX optimization

Previous interface: Required viewing each holder group under different tabs.

New interface: All key shares are displayed together, with labels indicating Main Key holders. Recovery Keys can be managed through the upper-right entry.

Recovery key configuration

Users can choose between Self Recovery and Third-Party Recovery. In both modes, the key share stored within Cobo’s multi-cloud infrastructure participates in recovery. Recovery without this stored key share is no longer available.

For advanced MPC vaults

For advanced MPC vaults, users can customize the signing threshold (m/n). This feature requires activation and is designed for clients who need custom signing structures.

Naming optimization

For advanced vaults, keys are referred to as MPC Keys, categorized as Signing Keys and Standby Keys, with no longer separate designations for Main, Signing, or Recovery Keys.

Key share holders (signers) are categorized as Regular Signers and Standby Signers. Transactions are sent to Regular Signers.

Support for self-service configuration

Once enabled, clients can configure keys directly through the user interface on a self-service basis.

Previous interface:

New interface:

2. Security mechanism optimization

Integration with governance policies

Critical operations related to keys (such as creating Signing Keys and Recovery Keys, or re-creating a Main Key) are now integrated with Governance Policies. These operations trigger security verifications to ensure that all critical steps are secure and controllable.

Key share holder configuration constraints

The system now prohibits the same node from acting as a key share holder for multiple keys within the same vault, to prevent cross-use risks and strengthen overall security.

3. Summary of optimizations and impact

Summary of optimizations

Standard mode

Item	Before	After	Purpose
Naming	• Key share holder groups • Main Group • Signing Group • Recovery Group	• Key • Main Key • Signing Key • Recovery Key	Clearer and more intuitive concepts
UI/UX	Key management spread across multiple tab pages	Main and Signing Key information displayed clearly with labels; Recovery Key accessible from upper-right corner	Centralized information, easier operation
Recovery key configuration	Allowed recovery without participation by the key share stored within Cobo’s multi-cloud infrastructure	No longer supports recovery without participation by that stored key share	Simplifies configuration and ensures a secure, controllable recovery path

For advanced MPC vaults

Item	Before	After	Purpose
Naming	• Main Group, Signing Group, Recovery Group • Signers	• MPC Keys • Regular Signers, Standby Signers	More intuitive structure and terminology
UI/UX	No interface support; required manual configuration via scripts	Clients can self-configure through the UI after enabling advanced mode	Reduces ambiguity and ensures key security

General security mechanism enhancements

Item	Before	After	Purpose
Integration with governance policies	None	Critical key operations integrated with governance policies	Enhances operational security and control
Key share holder configuration	Allowed the same node to hold multiple key shares in one vault	Prohibits duplicate participation of nodes in multiple key shares	Prevents potential security risks

Impact on existing keys

This optimization does not affect existing keys. Keys created before the optimization will retain their original structure and functions, and remain fully usable. The interface will present the existing key information in the new format.