(IDGConnect) The impact of quantum computing on our current public-key cryptography results from our basing them on very particular mathematical problems which are very hard for everyday computers to solve, but very easy for (as yet theoretical) quantum computers. Most communications which involve a potentially-untrustworthy entity are at risk, while any purely “local” uses of encryption are generally safe. Digital signatures, public key encryption and key exchange are the main vulnerable practices.
The good news is that, for every mainstream quantum-vulnerable algorithm and use case, several quantum-resistant replacements are waiting “in the wings”. Compared to the millennium bug, the amount of effort required to quantum-proof our communications will be much greater, but if these algorithms can be successfully deployed and integrated into all present-day applications, the arrival of quantum computers will hopefully be something of a non-event. HTTPS, SSH, VPN, IPSEC connections can all be switched over to using quantum-proof algorithms, with no outward sign of the different cryptography employed within.
The main advice would be to start preparing now for the arrival of quantum computers.Be “crypto-agile”: crypto agility is the ability to easily substitute one algorithm for another.