While quantum computing remains a largely theoretical threat to blockchain for now, some projects are already preparing for the possibility.
Fintech company Ripple has released a detailed four-phase roadmap aimed at making XRP Ledger, a decentralized layer-1 blockchain, quantum-resistant, with the goal of being fully ready by 2028. XRP is the fourth largest digital asset in the world by market capitalization and is the native token of the XRP Ledger. Ripple’s solution uses XRP Ledger, XRP and other digital assets. Ripple is also one of the many developers building and contributing to the XRP Ledger (XRPL).
Ripple’s announcement comes weeks after Google warned that quantum computers could attack Bitcoin, the world’s largest blockchain, with less computing power than previously estimated, prompting some analysts to suggest 2029 as Q-Day, the so-called deadline for building defenses against such machines. Bitcoin developers are also already working on risk reduction measures.
We first understand the threats facing XRPL and then discuss the four-phase plan.
Quantum Risks of XRPL
Quantum computers have three impacts on the XRP ledger that also apply to most other blockchains.
First, every time an XRPL account signs a transaction, its public key becomes visible on the blockchain. It’s like writing your mailing address on the outside of an envelope so anyone can see where it comes from, but without the private key they still can’t see what’s written inside.
However, a quantum computer can reverse-engineer the private key based on the published public key, thereby draining the tokens you hold.
Secondly, accounts that hold coins for a long time have the highest risk. The longer a public key remains on the chain, the longer it will be available for future quantum attackers to target it.
Finally, the team added that building quantum-resistant systems is not only a technical challenge, but also an operational challenge, as it is relevant to every XRP holder and every application built on the XRP Ledger.
Collectively, these things require structured responses.
four-phase plan
The first stage, “Q-Day Preparation” is an emergency measure designed to protect exposed public keys and long-held accounts if quantum computers arrive faster than expected.
In this case, Ripple will implement a so-called hard transition: the network will no longer accept classic public key signatures, requiring all funds to be migrated to quantum-safe accounts.
This phase also looks into providing secure recovery for all account owners through zero-knowledge proofs, a method of mathematically proving that you own a key without revealing the key itself. This will allow holders to move funds even in the event of a compromise, ensuring no one is left out.
second stage The plan is already underway and is expected to be completed in the first half of 2026. The plan involves Ripple’s applied cryptography team conducting a comprehensive assessment of quantum vulnerabilities across the XRPL network and testing defenses recommended by the National Institute of Standards and Technology, the U.S. government’s global cybersecurity standards body.
But these defenses are not without cost. For example, post-quantum cryptography uses larger keys and signatures, which could put pressure on the ledger. So the team is also weighing what system changes might be needed.
To accelerate this phase, Ripple is partnering with quantum security research firm Project Eleven for validator-level testing, developer network benchmarking, and early custodial wallet prototypes.
The third stageIt is expected to be completed in the second half of 2026 and involves the controlled integration of post-quantum measures. During this phase, Ripple will begin integrating quantum-resistant signatures with existing signatures on its developer test network. It will allow developers to test and build new cryptographic technologies without disrupting live networks and existing users.
This phase therefore directly addresses the third implication, which is that migration, while a huge operational undertaking, must not disrupt existing operations.
At the same time, this effort goes beyond replacing today’s signature methods. The team is rethinking the broader cryptography that underpins XRPL and exploring quantum-resistant methods for privacy and secure data processing, which will be important for features such as compliant tokenization and confidential transmission.
“This phase is a combination of experimentation and system design. We’re not just asking ‘What works cryptographically?’ ” What we’re asking is “What works for XRPL at scale?” ” said the team.
Stage 4 Marking a full transition from experimentation to full deployment, it is targeted for completion in 2028. “We will design, build and propose a new amendment Ripple’s team stated: “The XRPL ecosystem is used to native post-quantum cryptography and begin the transition of the network to PQC-based signatures at scale.”
These four stages mean the migration path can be seamless and significantly less painful, which could be a material advantage as Q-Day approaches.
