Quantum computers are developing faster than ever as we saw IBM and Honeywell both announce 64 qubit computers in the past month. Additionally, the federal government is allocating more money towards quantum computing and has awarded $625 million to fund five new quantum information centers.
While this is great for application development, it's horrible for security. Public-key cryptography including RSA and elliptical curve cryptography are both at risk with a fully developed quantum computer using Shor's algorithm. Shor's is a polynomial-time quantum computer algorithm for integer factorization that is capable of cracking 2048 bit RSA. This is a very serious issue as most secure applications depend on public-key cryptography. Additionally, there are algorithms that have been published out of China that show quantum annealers can be used to hack RSA. Fujitsu has a digital kneeler with a roadmap to 1 million cubits over the next 12 months. This would be enough to break RSA. The good news is that the National Institute of standards and technology (NIST) has been running a competition over the past few years to find the top public-key cryptography algorithms that could stop quantum computers from hacking. We expect that NIST will announce the finalists sometime in 2022 if not sooner.
Some estimate that powerful and practical quantum computers are years away. Nonetheless, data is being stolen by hackers on a daily basis and even if hackers cannot un-encrypt the data today, they will later as they have access to more powerful computers. If that data has a shelf life longer than the time it takes for quantum to come online, then it is at risk. Things like Social Security numbers, driver's license numbers, dates of birth, military or government secrets, and other valuable data have decades of value for hackers. So it is vitally important to protect data now using post-quantum encryption so that even if it is stolen, it has a higher likelihood of remaining intact as hackers try to chip away at its encryption.
The bottom line is that quantum computers are on the way and will have an impact on humanity. Their exponential power to solve intractable problems will one day be one of our greatest assets and at the same time, one of our greatest liabilities.