Fortunately, symmetric key encryption methods are not in danger because they work very differently and can be secured simply by increasing the size of the keys they use, that is, unless mathematicians can find a way for quantum computers to also break up . But even increasing the key size cannot protect the existing public key encryption algorithms of quantum computers. New algorithms are needed.
What would be the repercussions if quantum computers break the encryption we currently use?
Yes, it’s bad. If public key encryption is suddenly broken without a replacement, digital security would be severely compromised. For example, websites use public key encryption to keep Internet connections secure, so sending sensitive information through websites would no longer be secure. Cryptocurrencies also rely on public key encryption to secure their underlying blockchain technology, so the data on their ledgers would no longer be trusted.
There is also concern that hackers and nation-states may be hoarding highly sensitive government or intelligence data (data that they cannot currently decrypt) to decrypt later once quantum computers become available.
How is work progressing on quantum-resistant algorithms?
In the US, NIST has been looking for new algorithms that can withstand quantum computer attacks. The agency began accepting public submissions in 2016, and so far it’s been whittled down to four finalists and three backup algorithms. These new algorithms use techniques that can withstand quantum computer attacks using Shor’s algorithm.
Project leader Dustin Moody says NIST is slated to complete standardization of the four finalists by 2024, which involves creating guidelines to ensure the new algorithms are used correctly and safely. The remaining three algorithms are expected to be standardized in 2028.
The work of verifying candidates for the new standard falls mainly to mathematicians and cryptographers at universities and research institutions. They present proposals for post-quantum cryptographic schemes and look for ways to attack them, sharing their findings by publishing papers and leveraging each other’s different attack methods.
