Quantum resistance (Bitcoin Optech Topics)

Bitcoin Optech's "Quantum resistance" topic page is a neutral technical explainer and index rather than an opinion piece. It is maintained continuously, so it doubles as a current map of the engineering debate.

It explains that bitcoin's hash functions (SHA-256, RIPEMD-160) are weakened but not broken by Grover's algorithm, which roughly halves their effective security in bits, while ECDSA and Schnorr public keys can be fully broken by Shor's algorithm on a sufficiently capable quantum computer.

The page also documents a practical reason developers have been cautious: quantum-resistant signature schemes tend to have much larger keys and signatures, with direct costs in fees and block space. It tracks ongoing proposals and discussions, including BIP-360 and related migration ideas.

Because it aggregates primary discussions and newsletter coverage over time, it is a good starting point for following the topic as it develops.