Quantum Threat Looms Over Cryptocurrency Ecosystem

Blockchain developers are racing to protect against the looming threat of quantum computers. Currently, no top-20 cryptocurrency is fully quantum-safe, but Bitcoin and Ethereum both have upgrade paths underway.

Quantum computers could potentially crack public keys with ease, making it possible for a hacker to derive private keys in minutes instead of the universe's age in years. Google Quantum AI has demonstrated this capability with its 1,200- to 1,450-logical-qubit machine, which can perform Shor's algorithm in under an hour.

Cryptocurrency developers are working on post-quantum encryption algorithms, but implementing them is a complex task. The new codes are larger and slower than existing ones, requiring significant storage upgrades for each node on the network. For example, Microsoft and IBM already offer post-quantum security in their cloud and security products.

Bitcoin's contribution to quantum safety comes from BIP 360, which adds a new address type called P2MR. This allows users to opt into quantum-resistant signatures later without disrupting the entire network. Ethereum is also working on upgrades, with Vitalik Buterin's Lean Ethereum plan mapping out a multi-year swap of validator signatures for hash-based ones.