The advancement of quantum computing is prompting concerns about the long-term security of major cryptocurrencies like Bitcoin, Ethereum, and XRP. Analysts estimate that approximately 6.89 million BTC could be vulnerable to future quantum attacks due to exposed public keys. While Bitcoin and Ethereum rely on elliptic curve cryptography, the XRP Ledger's validator-based consensus model may allow for quicker adaptation to quantum-resistant encryption if needed. As technology companies and universities advance quantum research, blockchain networks are being evaluated for their resilience against potential future computing power. Although quantum computers capable of breaking modern encryption do not yet exist at scale, the crypto industry is increasingly focusing on long-term security strategies. The central issue for blockchain networks may not be current safety, but their ability to evolve quickly if encryption methods are challenged. Governance models could play a crucial role in adapting to quantum threats. Bitcoin and Ethereum's decentralized structures provide strong security but may slow protocol upgrades. In contrast, the XRP Ledger's model could facilitate faster adjustments to cryptographic standards, highlighting the importance of flexibility in future-proofing blockchain security.