Tiger Research has issued a report highlighting the potential threat quantum computing poses to blockchain security, specifically targeting Bitcoin and Ethereum. The report predicts that 'Q-Day,' the point at which quantum computers could compromise blockchain cryptography, could occur within 5 to 7 years. It identifies Shor and Grover algorithms as direct threats to the cryptographic foundations of Bitcoin, namely ECDSA and SHA-256. In response, the report notes that post-quantum cryptography (PQC) standards such as Kyber, Dilithium, and SPHINCS+ are being considered to mitigate these risks. Bitcoin is exploring a hybrid migration strategy, while Ethereum plans to utilize its adaptable architecture to integrate PQC at the account level. Despite these efforts, both networks face significant challenges in implementing these security measures before the advent of quantum computing.