Quantum computing is emerging as a significant threat to blockchain security, with the potential to break the encryption that underpins Bitcoin and other systems. The ECDSA algorithm used by Bitcoin, developed in the 1980s, is particularly vulnerable to quantum decryption techniques like Shor's algorithm. This vulnerability puts early Bitcoin wallets, including those of Satoshi Nakamoto, at risk. In response, blockchain networks are exploring quantum-resistant strategies. Ethereum is experimenting with multi-path approaches, while Solana offers optional quantum-safe vaults. New projects such as Quranium and QRL are being developed with quantum resistance as a core feature. Experts stress the need for the industry to transition to quantum-safe algorithms by 2035 to safeguard against future threats.