MIT professor argues math can make blockchains quantum-safe without quantum computers

Quantum safety without quantum machines

MIT professor and Optimum co-founder Muriel Médard argues in a CoinDesk opinion column that blockchains can become quantum-safe without quantum computers. The solution, she says, is better math.

The column, published Sept. 13, says the industry should not wait for quantum computers to arrive. Médard warns that sophisticated actors, including nation-states, are already collecting encrypted data so they can decrypt it later. She calls this strategy "harvest now, decrypt later."

Key claims in the column

• Traditional encryption such as RSA relies on the difficulty of factoring large prime numbers. In 1994, MIT's Peter Shor showed that a quantum computer could solve such problems exponentially faster, according to the column.
• Post-quantum cryptography (PQC) is a field of encryption designed to resist quantum attacks. The classic McEliece system remains one of the strongest PQC approaches, but the column says it is so computationally heavy that it is impractical for many uses.
• The Ethereum Foundation has backed ZKnox, a research group working on open-source post-quantum tools that could reduce gas fees by up to 12 times, the column says. Gas fees are payments users make to process transactions on a blockchain.
• Algorand is protecting its entire chain history with FALCON signatures for post-quantum resilience, according to the column.

How RLNC works

Random Linear Network Coding (RLNC) is a coding method developed over two decades in Médard's MIT lab. It breaks data into coded equations that can be mixed and recombined as they travel through a network.

With PQC encryption via RLNC, only part of the data needs to be encrypted. Médard says encrypting about 10% of the coded equations protects 100% of the dataset while cutting 90% of the computational burden.

Because RLNC is based on pure math, it can be embedded at any level of the Web3 stack, she writes. Web3 is a term for blockchain-based internet applications. Médard says her team has also combined RLNC with hardware chips, showing that it can scale down to silicon and into the core of blockchain nodes.

She adds that RLNC could serve as a "quantum-safe memory layer" for blockchains, allowing data propagation, storage, and writing to the chain to inherit quantum security without encrypting every transaction end-to-end.

Facts, claims, and what is still unclear

The article is an opinion piece, and CoinDesk notes that the views expressed are those of the author. The claims about RLNC, ZKnox, and Algorand come from the column and are not independently verified in the source material.

The column does not provide a timeline or announced rollout for RLNC on any blockchain. It also does not give test data showing the method running on a live public blockchain.

Why this matters

Médard says blockchains are uniquely exposed because they permanently store money, identity, contracts, and governance. She argues that institutions will not move their financial systems, identity systems, or governance models to public blockchains unless those systems are provably future-proof.

In her view, waiting for quantum computers would be too late because data can already be harvested today.

Sources

• CoinDesk