Distributed Key Generator (DKG)

The Distributed Key Generator (DKG) is a critical protocol component responsible for provisioning cryptographic keys for a secure, time-locked encryption/decryption mechanism. This mechanism is formalized via Single Key Delay Encryption (SKDE).

Initially, the DKG is operated by Radius, with plans for transitioning to decentralized operator management to further enhance network robustness.

Core Functions

DKG is designed to provide the foundational certainty necessary for high-value operations:

• Byzantine Fault Tolerance (BFT): Implements BFT to safeguard the system. By decentralizing key management, DKG ensures that operator failure does not compromise the cryptographic security of the entire system.

• Distributed Architecture: Multiple specialized nodes decentralize the key management process, eliminating the single point of failure inherent in centralized key storage.

• Time-Lock Encryption: Keys for encryption are available immediately; decryption keys are released only after pre-determined time intervals.

• SKDE Integration: Seamlessly integrates with the SKDE framework to guarantee the integrity of time-locked cryptographic operations.

• High Performance: Achieves efficient key generation and consensus via asynchronous task processing.

Architecture

DKG operates through four specialized node types, each contributing to the security and integrity of the key lifecycle:

Node Roles

Role	Purpose	Key Responsibilities
Authority	Trusted Setup Manager	Constructs, manages, and securely distributes SKDE parameters.
Committee	Key Generation Leader	Generates encryption keys and coordinates consensus among nodes.
Solver	Decryption Provider	Computes the time-lock decryption keys.
Verifier	Network Monitoring	Detects, monitors, and reports any Byzantine (malicious or faulty) behavior within the network.

How DKG Works

DKG utilizes a time-locked encryption model:

1. Setup Phase: The Authority node initializes the system by generating and distributing foundational SKDE parameters.

2. Key Generation: Committee nodes create the encryption keys corresponding to scheduled time intervals.

3. Immediate Access: Encryption Keys are immediately available for external services.

4. Time-Locked Release: Solver nodes compute and release the corresponding decryption keys after pre-determined delays.

5. Verification: Verifier nodes continuously monitor the network operations, ensuring all nodes adhere to the protocol and maintaining fault tolerance.

Operational Lifecycle

Key States and Transitions