break them fast enough. However, quantum computers will be able to solve hard mathematical problems exponentially faster than digital supercomputers. This will make asymmetric cryptography obsolete and will weaken other cryptographic keys and hashes. Theoretically, a fully functioning quantum computer could break an asymmetric key in a matter of minutes. Public keys are especially vulnerable because most of them are based on the factorization problem: it is hard for digital computers to find two prime numbers from their product. Quantum computers, by contrast, can do
/2 , n being the number of bits used for the hash output. Therefore, longer hash functions like the SHA-3 family, which typically generate 256-bits outputs, are considered quantum safe and expected to remain as approved standards for now. Public (or asymmetric) keys, however, can become obsolete with quantum computing. Theoretically, a fully functioning quantum computer can break an asymmetric key in a few hours by using Shor’s algorithm and related optimizations ( Gidney et al., 2019 ). Furthermore, researchers believe that advancements in quantum computing