The rise of quantum computing has sparked discussions about its potential impact on legacy blockchains, with Google suggesting that powerful machines could exploit them more easily than previously thought.
Experts believe that XRP’s architecture might be less susceptible to these quantum threats compared to Bitcoin. The digital token XRP operates on the open-source, decentralized XRP Ledger (XRPL), developed by fintech company Ripple.
Fundamentally, major blockchains use a private key for signing and executing transactions. A public key is derived mathematically from this private key, generating a wallet address shared to receive funds.
The quantum threat involves the potential of a powerful machine using Shor’s algorithm to reverse-engineer private keys from exposed public keys during transactions, potentially draining accounts.
This week, XRP Ledger’s validator Vet conducted an audit and found approximately 300,000 XRP accounts holding 2.4 billion XRP that haven’t sent funds, thus never exposing their public keys and inherently making them quantum-safe.
However, there are dormant whale accounts with exposed public keys from transactions at least five years ago. These could be vulnerable if a quantum computer emerges suddenly. Vet identified two such accounts, holding 21 million XRP or about 0.03% of the circulating supply.
XRP Ledger allows for signing key rotation, enabling users to change their signing keys without moving funds—akin to changing a house lock while staying put. Mayukha Vadari from Ripple highlighted the “escrow feature” as another protective measure against quantum threats. Funds in escrow with time locks are protected by logic rather than cryptography.
The quantum threat is perceived as more severe for Bitcoin due to its scale. Early mined bitcoins, particularly those using P2PK format, directly exposed public keys, making them vulnerable. Google estimates around 6.9 million BTC (about 35% of the circulating supply) are at risk compared to XRP’s minimal exposure.
Bitcoin holders face challenges since their blockchain lacks key rotation features, forcing them to transfer funds to new addresses with unseen public keys. This transaction process temporarily exposes old public keys, presenting a theoretical quantum threat. Nonetheless, Bitcoin developers are working on proposals for enhancing quantum resistance.