Ripple's Plan to Make XRP Ledger Quantum-Proof by 2028

Although quantum computing is still largely a theoretical threat to blockchain technology, some projects are taking proactive measures to prepare for its potential impact. Fintech company Ripple has unveiled a detailed, four-phase plan to make the XRP Ledger, a decentralized layer-1 blockchain, resistant to quantum attacks, with the goal of achieving full readiness by 2028. The XRP Ledger is the native platform for XRP, the world's fourth-largest digital asset by market capitalization, and Ripple's solutions utilize the XRP Ledger, XRP, and other digital assets. Ripple is also one of many developers contributing to the XRP Ledger. This announcement comes on the heels of Google's warning that a quantum computer could potentially attack Bitcoin, the world's largest blockchain, with less computational power than previously estimated, prompting some analysts to suggest that 2029 could be the deadline for building defenses against such a machine. Bitcoin developers are also working on measures to mitigate this risk. To understand the threat to the XRP Ledger, it is essential to first examine the implications of quantum computing on the platform. A quantum computer poses three significant risks to the XRP Ledger, which are equally applicable to most other blockchains. Firstly, whenever an XRP Ledger account signs a transaction, its public key becomes visible on the blockchain, making it possible for anyone to see the origin of the transaction, but not its contents, without the private key. However, a quantum computer can reverse-engineer the private key from the exposed public key, potentially draining coin holdings. Secondly, accounts that have held coins for extended periods are at the highest risk, as the longer the public key remains on-chain, the more time a potential quantum attacker has to target it. Lastly, building quantum-resistant systems is not only a technical challenge but also an operational one, as it affects every XRP holder and application built on the XRP Ledger. These factors warrant a structured response. Ripple's four-phase plan is designed to address these risks. Phase 1, called Q-Day readiness, is an emergency measure aimed at protecting exposed public keys and long-held accounts in the event of an unexpected quantum computing breakthrough. In such a scenario, Ripple will implement a hard shift, where classical public-key signatures will no longer be accepted by the network, requiring all funds to migrate to quantum-safe accounts. This phase also involves enabling safe recovery for all account owners via zero-knowledge proofs, allowing holders to migrate funds even in a compromised scenario. Phase 2 is currently underway, with a target completion date in the first half of 2026. During this phase, Ripple's applied cryptography team will conduct a comprehensive assessment of quantum vulnerability across the XRP Ledger network and test defenses recommended by the National Institute of Standards and Technology. However, these defenses come with costs, such as the use of larger keys and signatures, which can strain the ledger. To address these challenges, Ripple is working with quantum security research firm Project Eleven to conduct validator-level testing, developer networking benchmarking, and early custody wallet prototypes. Phase 3, scheduled for completion in the second half of 2026, involves the controlled integration of post-quantum measures. In this phase, Ripple will begin integrating quantum-resistant signatures alongside existing ones on its developer test network, allowing developers to test and build against the new cryptography without disrupting the live network and existing users. This phase will also involve rethinking the broader cryptography underpinning the XRP Ledger and exploring quantum-resistant approaches to privacy and secure data processing. The final phase, Phase 4, marks the full transition from experiment to deployment, with a target completion date of 2028. During this phase, Ripple will design, build, and propose a new amendment to the XRP Ledger ecosystem for native post-quantum cryptography and begin transitioning the network to PQC-based signatures at scale. The four-phase plan is designed to ensure a seamless and less painful migration path, which could provide a significant advantage as the deadline for quantum computing approaches.