Coinbase Develops Post-Quantum Custody Plan for Roughly $250 Billion

Coinbase is developing post-quantum custody safeguards for roughly $250 billion in institutional assets as Bitcoin (BTC) and other blockchains consider how to protect digital assets from future quantum-computing threats.

The company is designing its systems to support multiple post-quantum signature standards rather than relying on a single method. Different networks may ultimately adopt different approaches, requiring Coinbase's custody infrastructure to accommodate more than one outcome.

Coinbase currently uses multiparty computation, or MPC, in its custody systems. MPC divides control of a private key among several parties, allowing a transaction to be approved without keeping the complete key in one place.

That structure may not work efficiently with every post-quantum signature system. Hash-based designs, in particular, can lack the mathematical properties used to split traditional cryptographic keys across multiple parties. Researchers are working on possible solutions, but the technology remains experimental.

Coinbase is also examining a fallback architecture based on programmable hardware security modules (HSMs). Under that design, private keys protected with post-quantum cryptography would be assembled within physically secured devices at private data centers.

The approach would rely on strict limits on physical access, protections against side-channel attacks and controls over software uploads. Those safeguards are intended to reduce the risks of handling a complete key inside a single device, even temporarily.

The company has not established a deadline for completing its post-quantum security measures. Its broader objective is to maintain a custody system capable of supporting the signing method ultimately selected by Bitcoin and other blockchains.