$250 Billion Behind MPC — But What Happens After Quantum?

Coinbase reportedly safeguards roughly $250 billion in customer assets, including assets held for major institutions such as BlackRock. A major part of that security architecture relies on Multi-Party Computation (MPC)—cryptographic protocols that allow multiple parties to jointly perform sensitive operations without exposing a complete private key to any single participant.

But what happens when today's cryptography meets tomorrow's quantum computers?

In a recent episode of MFTV, Yehuda Lindell, Head of Cryptography at Coinbase, raises a difficult problem: some emerging post-quantum digital signature schemes may be extraordinarily difficult—or potentially infeasible—to integrate with MPC.

That matters because replacing a signature algorithm isn't necessarily as simple as swapping one cryptographic primitive for another. When the signing process itself is distributed across multiple parties, the underlying mathematics, communication requirements, computation and security assumptions all have to work within the MPC framework.

Watch the discussion with MARA Foundation Head Isabel on MFTV.

“Can post-quantum signatures survive quantum computers?”

OR

Can the entire custody infrastructure built around today's cryptography migrate to them without breaking the machinery underneath?