On the Ethereum side, Vitalik is already paying close attention to the issue of quantum-resistant threats, and V has provided a quantum-resistant roadmap. The problems faced by $BTC and $ETH are quite similar. The main issue is that the current cryptographic signature method (ECDSA) can be cracked by quantum computing, which means private keys can be derived from public keys. Compared to $BTC, Ethereum is clearly progressing faster, but both face a tricky issue: zombie addresses with lost private keys could become easy targets. Ultimately, whether through migration or a fork, users will need to take action themselves. However, coins with lost private keys are like floating in the air, ownerless and uncontrolled. Once quantum computers can crack them, these coins could be "picked up" by someone. Unless a hard fork is implemented at a specific time to freeze or destroy all unmigrated coins, but this approach obviously goes against the crypto spirit of $BTC & $ETH. Especially for the $BTC community, such a move would likely be unacceptable. Currently, some "old coins" in $BTC are in a state where their public keys are exposed, which theoretically makes them vulnerable to quantum attacks. Of course, this issue also exists on Ethereum, but Ethereum has the advantage of more tools and greater flexibility. After all, it’s programmable. For example, Vitalik’s roadmap emphasizes using AA (Account Abstraction) to handle user signature issues, allowing users to directly upgrade account security (quantum-resistant) without needing to transfer all assets. However, for zombie coins with lost private keys, both sides currently have no solution. Overall, comparing the two, Ethereum’s quantum-resistant engineering might be more complex but easier to push forward. With a large number of ecosystem developers, coordination is easier. Plus, my gut feeling is that Ethereum users are quicker to accept and adapt to changes. After all, Ethereum itself is a system used daily, constantly iterating and upgrading—a platform led by developers and applications. Bitcoin, on the other hand, tends to be more conservative. Its primary characteristic is value storage, and many users remain in a state of low or even no activity for years.