Although quantum computing is currently still primarily a theoretical threat. Some blockchain projects are already preparing for this possibility.
Fintech company Ripple has released a detailed four-phase roadmap aimed at making the decentralized Layer-1 blockchain XRP Ledger quantum-resistant, with the goal of full implementation by 2028. The fourth-largest digital asset by market capitalization, XRP is the native token of the XRP Ledger. Ripple’s solution utilizes the XRP Ledger, XRP, and other digital assets. Ripple is also one of many developers building on and contributing to the XRP Ledger (XRPL).
Ripple's announcement was released weeks later. Google warned that quantum computers could pose a potential threat to Bitcoin. The world's largest blockchain, Bitcoin, has lower computational power than previously anticipated, prompting some analysts to set 2029 as the "Q-day"—the deadline for implementing defenses against such quantum attacks. Bitcoin developers have also begun taking steps to mitigate the risk.
Let’s first understand the threats facing XRPL, then discuss the four-phase plan.
Quantum risk facing XRPL
Quantum computers have three impacts on the XRP Ledger, which also apply to most other blockchains.
First, every time an XRPL account signs a transaction, its public key is revealed on the blockchain. This is like writing your mailing address on the outside of an envelope—anyone can see who sent the envelope, but without the private key, they still cannot see what’s inside.
However, quantum computers can reverse-engineer the private key from the exposed public key, thereby depleting your cryptocurrency assets.
Second, accounts that hold cryptocurrencies long-term carry the highest risk. The longer a public key remains on the chain, the more time future quantum attackers have to target it.
Finally, the team added that building a quantum-resistant system is not only a technical challenge but also an operational one, as it relates to every XRP holder and every application built on the XRP Ledger.
In summary, these matters require a systematic approach.
Four-phase plan
In the first phase, this emergency initiative, named Q-Day preparation, aims to protect exposed public keys and long-held accounts in case quantum computers arrive sooner than expected.
In this scenario, Ripple will implement a so-called "hard shift": the network will no longer accept traditional public key signatures and will require all funds to be migrated to quantum-secure accounts.
This phase will also explore how to provide secure fund recovery solutions for all account holders using zero-knowledge proofs. Zero-knowledge proofs are a mathematical method that allows you to prove you possess a key without revealing the key itself. This will enable account holders to migrate their funds even if their account is compromised, ensuring no one is locked out.
The second phase of this project is already underway and is expected to be completed in the first half of 2026. The project involves Ripple’s applied cryptography team conducting a comprehensive assessment of quantum vulnerabilities in the XRPL network and testing countermeasures proposed by the National Institute of Standards and Technology, the U.S. government’s global standard-setting body for cybersecurity.
But these defensive measures come at a cost. For example, post-quantum cryptography uses larger keys and signatures, which may put pressure on the ledger. Therefore, the research team is also weighing the pros and cons and exploring what changes may be needed for the system.
To accelerate this phase, Ripple has partnered with the quantum-safe research company Project Eleven to conduct validator-level testing, developer network benchmarking, and early-stage custodial wallet prototype development.
Phase three of the project is scheduled for completion in the second half of 2026 and involves the controlled integration of post-quantum technologies. In this phase, Ripple will begin integrating quantum-resistant signatures alongside existing signatures on its developer test network. This will enable developers to test and build applications based on the new cryptographic technologies without affecting the existing network or users.
Therefore, this stage directly addresses the third issue: although migration is a significant undertaking, it must not disrupt methods that have already proven effective.
At the same time, this work extends beyond merely replacing existing signature methods. The team is rethinking the broader cryptographic principles underlying the XRPL and exploring quantum-resistant approaches to privacy and secure data processing, which are essential for functionalities such as compliant tokenization and confidential transmission.
“This stage combines experimentation with system design. We’re not just asking, ‘What works cryptographically?’—we’re also asking, ‘What works at scale on XRPL?’” the team said.
Phase four marks a complete transition from experimentation to full deployment, with the goal of completion by 2028. “We will design, build, and propose a…” the Ripple team stated: “We will migrate to the XRPL ecosystem to implement native post-quantum cryptography and begin large-scale transition of the network to PQC-based signatures.”
These four stages mean the migration path can be seamlessly connected, significantly reducing friction—a substantial advantage as Q-day approaches.