The $XRP Ledger has a plan to protect user accounts from future quantum computers, and it won’t cost users anything extra in fees.

A design in the $XRP Ledger Foundation’s quantum study would let owners add a quantum-resistant signing key to their accounts and switch off the original one. It’s part of the Foundation’s 2027 protocol roadmap, updated Nov. 4.

The threat it guards against is already sitting onchain. Every time an account signs a transaction, it reveals a public key the network uses to check the owner’s approval. A powerful enough quantum computer could work backward from that key to the secret that controls the account. Any account that has ever sent a payment, every exchange wallet included, has exposed that key.

Under the design, owners would turn off the old key once the new one is in place, closing the route an attacker could otherwise use.

A standard key, same fee

The new key uses ML-DSA-44, a signature scheme the U.S. standards body NIST approved in 2024 specifically to stand up to quantum attacks.

It’s bulkier than what the ledger uses today. The key and signature together take 3,732 bytes, compared with 105 bytes for a regular payment, adding about 3.6 KB to each protected transaction. Counting history and database overhead, the Foundation puts storage at 5,331 bytes per protected payment against a 1,704-byte baseline.

Users wouldn’t pay for that. The proposal keeps the base fee where it is, and because $XRP Ledger fees are destroyed, the operators who run the network take on the extra storage.

Work is still under way. Developers are fixing a mismatch in which the Python prototype and the server and JavaScript versions can generate different keys from one starting seed. They also have yet to publish tests of how the network runs when all of its validators, the computers that agree on the ledger’s history, use the new signatures.

The roadmap sets aside $215,000 to $255,000 for review and auditing of this amendment, plus 640 hours of development. Across all 24 amendments on the roadmap, the budget runs from about $5 million to nearly $6 million.

Ripple is targeting a full quantum transition by 2028. The Foundation’s migration study is scheduled for the first half of 2027, with development and auditing to follow in late 2027 or 2028.