Ripple is building a multi-stage plan to prepare the XRP Ledger (XRPL) for an eventual shift to post-quantum cryptography, setting a 2028 target for full readiness.
This comes as advances in quantum computing force blockchain developers to think more concretely about how existing security systems may need to change in preparation for “Q-day.”
The company said the work will begin immediately with testing of quantum-resistant signatures, hybrid deployments that run alongside current systems, and a fallback process for moving users to safer accounts if existing cryptography is ever broken faster than expected.
The plan places Ripple among the first blockchain firms trying to translate a distant but increasingly defined risk into engineering deadlines, validator upgrades, and wallet migration procedures.
Notably, this move comes after XRPL’s developers integrated post-quantum cryptography into AlphaNet, the project’s public developer network.
Google research sharpens industry attention
Ripple’s new timeline comes as fresh quantum research has narrowed some of the assumptions developers once relied on when estimating how much time blockchains had before a credible attack became possible.
Ripple pointed to recent work from Google Quantum AI showing that roughly 500,000 physical qubits may be enough to attack ECDLP-256 cryptography, a reduction of about 20-fold from earlier estimates.
Google’s work suggested that once a machine of that scale exists, it may be possible to derive a private key from an exposed public key in minutes rather than over impractical time horizons.
That does not mean a machine capable of doing this exists today, nor does it imply that blockchains are on the verge of being broken.
However, it narrows the gap between theory and implementation enough to force difficult planning decisions, especially for networks supporting long-lived accounts, financial infrastructure, and regulated asset activity.
As a result, developers across rival blockchains, including Bitcoin and Ethereum, have begun debating defensive measures to protect their networks.
XRPL’s quantum computing readiness starting in 2026
Considering this, Ripple said its quantum readiness roadmap is split into four stages, beginning with contingency planning and early technical testing before moving toward a broader protocol-level transition.
The first stage is a recovery plan for what the industry often calls “Q-Day,” the point at which current public-key cryptography is no longer safe to trust.
In that scenario, Ripple said the ledger would need a process to move users away from classical signature systems and into post-quantum-secure accounts under emergency conditions.
One approach under study involves zero-knowledge methods built around post-quantum assumptions, allowing users to prove control of current keys without exposing them in a compromised environment.
Ripple described that stage as a safeguard designed for the case in which cryptographic assumptions fail before the rest of the migration is complete.
The second stage, scheduled for the first half of 2026, focuses on research, measurement, and testing.
Ripple said it plans to assess the network-wide effect of post-quantum cryptography on storage, bandwidth, transaction verification, and throughput, using algorithms recommended by the National Institute of Standards and Technology, or NIST.
That phase is expected to be heavy on performance analysis because post-quantum signatures are typically much larger than today’s elliptic-curve signatures, creating tradeoffs for networks built to settle quickly and at low cost.
The third phase, slated for the second half of 2026, would bring selected post-quantum schemes into controlled testing environments alongside the current signature model.
Ripple said candidate systems would be deployed on Devnet so developers and infrastructure operators can examine how hybrid signing works under conditions closer to real network activity.
The fourth phase is the production transition. Ripple said the stage will involve designing and proposing a new XRPL amendment for native post-quantum signatures, then coordinating adoption across the network to reach full readiness by 2028.
XRPL’s existing design could make migration easier
Ripple argued that the XRPL already has some features that could make migration less disruptive than on networks where users must move assets into entirely new accounts to adopt different key systems.
One of those features is native key rotation. At the account level, XRPL allows users to change key material over time without abandoning the account itself.
That means an account owner can replace vulnerable keys while preserving the account’s identity and structure, rather than shifting funds through a full wallet migration.
Ripple also said XRPL’s seed-based key generation model supports deterministic derivation of new keys, which could help during a coordinated transition to new cryptographic standards.
In practical terms, that offers a framework for generating and managing replacement key material in a more orderly way.
The company framed these features as pre-existing building blocks that reduce the amount of new architecture needed before a large-scale migration can begin.
That distinction is important because the challenge is to change cryptography across a live network that includes users, exchanges, custodians, validators, and application developers, all while keeping settlement predictable and minimizing the risk of asset loss or operational errors.
Testing will decide how far the plan can go
Ripple said the most difficult part of the transition may be the performance costs associated with stronger cryptographic defenses.
Post-quantum signatures can be far larger than current signature formats, which affects storage requirements, bandwidth consumption, and transaction validation times. Those costs become more significant at ledger scale, particularly on a network that emphasizes fast deterministic settlement.
The company said it is working with Project Eleven to speed up early testing, including validator-level experiments, Devnet benchmarking, and prototypes for post-quantum custody tools.
That collaboration is intended to help Ripple move faster through the research and testing stages while identifying infrastructure bottlenecks earlier.
Ripple also said its work extends beyond signatures alone. Engineers are studying cryptographic components relevant to zero-knowledge proofs and homomorphic encryption, fields that intersect with privacy and compliance features the ledger may need for tokenized assets and confidential transaction models.
That broader scope shows how a post-quantum transition could extend into more than one layer of the network. It could affect wallet design, validator software, custody systems, privacy tooling, and the developer environment that supports financial applications on XRPL.
