Compiled by GaryMa Wu said Blockchain
Original text:
https://x.com/el33th4xor/status/1866235573503230357
https://x.com/epr510/status/1866727421455765917?s=19
https://x.com/jeffrey_hu/status/1866689266237182370
Google's recent release of the quantum computing chip Willow has once again sparked discussions in the community about whether quantum computing could destroy Bitcoin. To help readers understand from multiple perspectives why quantum computing currently will not destroy Bitcoin, Wu said Blockchain has compiled the views of three KOLs.
Summary
Quantum computing currently will not destroy Bitcoin, but there is a potential threat. Since quantum computing capabilities are not yet sufficient to crack Bitcoin's hash and signature mechanisms, security is not a concern at this stage. However, Satoshi Nakamoto's million Bitcoins, due to using the early public key format (P2PK), are at risk of being compromised by quantum computing. The community can respond to future challenges by introducing quantum-resistant encryption or hard forks to freeze related assets.
Avalanche founder @el33th4xor
Despite the latest advancements in quantum computing being astonishing, it does not yet pose a threat to the security of cryptocurrencies. The reasons are as follows:
1. Differences in computational characteristics: While quantum computing has significant advantages in specific operations like factorization, it still struggles with other operations like inverting one-way hash functions. Additionally, the attack window for quantum computing is very brief, making attacks extremely difficult.
2. Designing quantum resistance: Systems like Bitcoin only reveal the hash of the public key before a transaction, rather than the public key itself, which protects the security of static funds. The public key is only revealed after the transaction is broadcast, and a quantum attacker needs to crack the key within a very short time. For example, in Bitcoin, this window is about 5 to 30 minutes; in Avalanche, it is only 1 second.
3. Future defense solutions: Avalanche has submitted a request on GitHub to introduce quantum-resistant Lattice encryption. Although the signature size is larger, the technology is well-prepared.
4. Satoshi Nakamoto's Bitcoin issue: The early adopted 'Pay to Public Key' (P2PK) format carries risks, and as quantum computing threats increase, the Bitcoin community may consider freezing these old format Bitcoins.
Chief Analyst at HashKey Group Jeffrey Hu
The Bitcoin protocol can be simplified into two parts: mining (based on hash) and transactions (based on elliptic curve signatures), both of which may be affected by quantum algorithms:
1. Current computational limitations: Attacking Bitcoin requires millions of physical quantum bits, while the Willow chip only has 105 physical quantum bits, far from reaching a threatening level.
2. Limited mining impact: Although Grover's algorithm can accelerate hash collisions, it does not break hash rules; it is merely like a more powerful mining machine.
3. Signature security: Older P2PK and the latest P2TR need to be cautious, but hash-based formats like P2PKH and P2SH are relatively safe. Address reuse may lead to risks; good usage habits are recommended, such as one key at a time, and transferring assets to more secure segregated witness addresses.
4. Future feasible measures: Introducing hash-based Lamport signatures or quantum-resistant Lattice encryption can be upgraded through soft forks.
Associate Professor Hu Yilin from Tsinghua University
The quantum-resistant upgrade for Bitcoin may be difficult to fully resolve through soft forks, primarily due to the following challenges:
1. Risk of old coins: Addresses that have previously exposed public keys may become unable to transfer funds in time due to users losing private keys or negligence, leading to a large number of 'revived' coins impacting the market. This requires a hard fork to permanently seal these old coins.
2. First mover advantage: Early adopters of quantum computers may concentrate and seize all dormant coins, which would have a dramatic impact on the market, especially if these technologies are in the hands of large companies or governments.
