Bitcoin and Ethereum are vulnerable to quantum computing; only the new chain is fully prepared.

According to Decrypt, concerns have been raised that Bitcoin and Ethereum are not prepared for potential quantum computer threats. Mystenlabs, the developer of Sui (SUI), explained in a report that "Blockchains using the current ECDSA signature system do not meet quantum security standards, and structural reforms are inevitable. Solana (SOL), Sui (SUI), Near (NEAR) and others have adopted the latest EdDSA signature method, creating a structure relatively resistant to quantum attacks. In contrast, Bitcoin and Ethereum remain exposed to ECDSA vulnerabilities such as random collisions and nonce reuse." Kostas Chalkias, co-founder of Mystenlabs, warned that "Most national institutions are planning to phase out existing algorithms (ECDSA, RSA) by 2030-2035, and for blockchains involving digital treasury, CBDC, and ETFs, a rapid quantum security transition is essential. If quantum computers can decrypt public key cryptosystems through Shor's algorithm, they could potentially reverse-track private keys from already exposed public keys. Depending on the past key generation method and exposed metadata, one cannot guarantee safety even if possessing the private key."