XRP Ledger Targets Quantum-Resistant Upgrade by 2028—The Risks and Costs
Key Takeaways
XRP Ledger is targeting quantum readiness by 2028, with new roadmap research outlining plans to implement ML-DSA-44 post-quantum signatures for accounts, validators, and validator list publishers.The upgrade presents significant technical challenges, including a 213% increase in transaction size, an estimated 1,040 development and review hours, and $215,000 to 255,000 in additional expenses.Other major blockchains are also preparing for quantum threats, including Ethereum, Solana, Bitcoin, and Starknet, as developers explore new cryptographic standards and network upgrades to protect against future quantum attacks.
XRP’s Path to Post-Quantum Cryptography
The research, published as part of the XRP Ledger Foundation’s 2027 protocol roadmap, examines introducing ML-DSA-44, a standardized post-quantum digital signature algorithm, across the blockchain’s accounts, validators, and validator list publishers.
The proposed change would allow users and network operators to replace existing cryptographic keys with alternatives designed to withstand attacks from sufficiently powerful quantum computers.
The research builds on Ripple’s previously announced goal of achieving full post-quantum readiness by 2028, but provides a more detailed assessment of the work required to reach that target.
Currently, XRP Ledger accounts use secp256k1 or Ed25519 cryptography, both of which could theoretically be compromised by sufficiently advanced quantum computers running Shor’s algorithm.
The concern extends beyond individual XRP wallets. Validators rely on cryptographic signatures to authenticate transactions and coordinate network consensus, while trusted validator list publishers help determine which operators participate in that process.
A successful attack against those systems could allow malicious actors to impersonate legitimate accounts or validators, potentially undermining network security.
The Foundation’s proposal would introduce ML-DSA-44 support throughout these systems, allowing users to migrate before existing cryptographic protections become vulnerable.
However, the upgrade would come with significant technical costs.
According to the research, transactions using the proposed quantum-resistant signatures could consume approximately 5,331 bytes of storage, compared with 1,704 bytes for a conventional payment. That represents an increase of roughly 213%, potentially affecting network bandwidth, transaction history storage, and operating costs.
The Foundation estimates that implementation would require approximately 640 development hours and 400 additional review hours, with projected review, auditing, and related expenses totaling between $215,000 and $255,000, excluding the initial development effort.
The research also identifies unresolved questions around transaction fees, account migration, and compatibility with existing software. Simply adding a quantum-resistant regular key would not fully secure an account if its original vulnerable master key remained enabled.
An implementation has already been tested on the network’s AlphaNet environment, but further development and security reviews are required before deployment.
The roadmap schedules a migration study for the first half of 2027, followed by development, review, and auditing in late 2027 or 2028. No mainnet activation date has been approved.
Ripple previously announced a four-phase quantum security strategy in April, including experimental deployments, contingency planning, and collaboration with security firm Project Eleven. That partnership includes research into hybrid signing systems combining traditional and post-quantum signatures, along with validator testing and custody wallet prototypes.
Blockchains Prepare Post-Quantum Moves
The XRP Ledger is not alone in preparing for the emerging threat.
Bitcoin developers are considering BIP 360, a proposal that would introduce a new output type intended to reduce public-key exposure. Just recently, a longtime Bitcoin Core developer proposed planting secret “quantum landmines” to potentially turn attempted quantum bitcoin thefts into potentially expensive mistakes.
Ethereum has incorporated quantum resistance into its longer-term roadmap, with proposed changes to validator architecture and account authentication targeting broader upgrades around 2029. Solana developers have explored the Falcon post-quantum signature scheme, while Starknet is researching a potential transition from Ethereum Layer 2 to an independent Layer 1 blockchain, partly to gain greater control over its post-quantum security roadmap.
Although no quantum computer has yet demonstrated the ability to break the cryptography securing major blockchains, the XRP Ledger Foundation argues that preparing early is essential because replacing cryptographic systems across a live network could take years.
If successfully deployed, the proposed amendment could position the XRP Ledger among the first major blockchains to support native post-quantum signatures for both ordinary accounts and validators.
