Google research says quantum computers could break Bitcoin's ECC by 2029

Google research says Shor's algorithm could break ECC with about 1,200–1,450 logical qubits and tens of millions of gates.

The paper moves the likely timeframe for practical quantum attacks on ECC to around 2029.

Blockchains and cryptocurrencies are especially vulnerable because public keys and transactions can be stored for later quantum cryptanalysis.

Google recommends migrating from ECC to post-quantum cryptography while there is time, but distributed blockchains face implementation challenges.