XRP Ledger weighs quantum-resistant account keys by 2028

The proposal would let users assign a post-quantum signing key and disable their existing master key without changing their account address. The XRP Ledger currently supports secp256k1 and Ed25519 signatures; the Foundation says sufficiently powerful quantum computers could eventually break the cryptography behind both. Public keys become visible when accounts sign transactions, creating a potential route to recover private keys if that threat becomes practical.

ML-DSA-44 was standardized by the US National Institute of Standards and Technology in August 2024. The Foundation estimates its public key would be 1,312 bytes and its signature 2,420 bytes. Including both, the data would total 3,732 bytes, compared with 105 bytes for equivalent key and signature information in a conventional transaction. With transaction history and database overhead, storage could reach 5,331 bytes per protected payment, versus a 1,704-byte baseline. The proposed amendment would keep the base fee unchanged: the minimum standard fee is currently 10 drops of XRP, though congestion can push costs higher.

The Foundation’s roadmap, updated November 4, calls for a migration study in the first half of 2027, followed by engineering work, reviews and security audits. An implementation branch has been tested on AlphaNet, but developers still need to address differences between Python, server and JavaScript implementations, as well as wallet compatibility and validator performance. Ripple’s four-phase post-quantum plan, published in April 2026, also includes algorithm testing, validator benchmarking and compatible wallet infrastructure.

The Foundation estimates 640 development hours and 400 hours of engineering review for the amendment. Listed costs total $215,000 to $255,000, excluding the development hours: $40,000 to $80,000 for Ripple review, $100,000 for an external audit, $50,000 for a reference implementation and $25,000 for Ledger hardware and other wallet updates. Exchanges, custodians and institutions with large balances are identified as likely early users.