What Does “Post-Quantum Secure” Mean in the Context of Cryptography?

Post-quantum secure refers to cryptographic algorithms that are resistant to attacks by a large-scale quantum computer. Current public-key cryptography, like that used in Bitcoin, is vulnerable to Shor's algorithm, which could efficiently break the underlying mathematical problems.

Post-quantum algorithms, such as those used in zk-STARKs, are being developed to ensure long-term security against future quantum threats.