The rise of quantum computing has sparked concerns about the potential risks it poses to blockchain security. Experts suggest that XRP's architecture may be better equipped to withstand these threats than Bitcoin's. XRP operates on the XRP Ledger, a decentralized, open-source blockchain that facilitates cross-border transactions through Ripple, a fintech firm.
A key difference lies in the exposure of public keys, which can be reversed-engineered by a powerful quantum computer using Shor's algorithm, potentially draining funds. Typically, public keys are exposed when sending transactions, making account activity a factor in quantum vulnerability.
A recent audit of the XRP Ledger found around 300,000 accounts holding 2.4 billion XRP had never sent funds, making them quantum-safe by default. In contrast, dormant whale accounts that have transacted in the past are at risk, but they only hold 0.03% of the circulating supply. The XRP Ledger's account-based system and signing key rotation feature allow users to swap their signing key without moving funds, reducing vulnerability. However, this feature is not foolproof, and long-dormant accounts may still be at risk.
Another defense against quantum risk is the escrow feature, which locks funds with a time lock, making them safe due to logic rather than cryptography. While the time lock protects funds, the account that locked them can still carry quantum risks. In comparison, Bitcoin's quantum threat appears more significant due to its scale and lack of a key rotation feature. A substantial portion of early bitcoin was mined using a format that exposed public keys directly, making them vulnerable to quantum attacks.
Approximately 6.9 million BTC, nearly 35% of bitcoin's circulating supply, are at risk. Bitcoin holders face a structural problem, as moving funds to a new address exposes the old address's public key, making it vulnerable to quantum attacks. Although Bitcoin developers have proposed initiatives to develop quantum resistance, XRP's unique features and architecture may provide it with an advantage in mitigating quantum computer threats.