The National Institute of Standards and Technology is following the example of the NSA, which last year announced it was time to develop and eventually transition to new cryptographic algorithms as the new and rapidly developing field of quantum computing begins to deprecate the current, standard algorithms.
This marks the beginning of a new era of cryptography, considering our current, tested and proven algorithms are utterly essential to the security of digital information transmission in everyday life. It is the fundamental protection we use on a daily basis to keep anything from personal information, credit card or banking information safe as it travels across the internet. Without effective cryptography to protect sensitive information, entire multi-trillion dollar businesses which rely upon security, such as internet commerce and banking, become threatened to extinction. Another important set of technologies which rely upon cryptography are anonymity and privacy services, such as VPN and TOR. Without cryptography, we are stripped of protection and left merciless before the powers of big government and corporate surveillance.
This is why the advent of quantum computing comes as a frightening revelation to many within the information technology industry. Regular digital computers function by using basic electronic units called bits which use electrical charges to represent two states, one or zero. Modern computers handle fundamental computation by manipulating these two transistor states.
This is where quantum computers differ, as they are not limited to the two states of a bit, on or off, 1 or 0. Instead, they utilize superposition, quantum entanglement and the principles of quantum mechanics to utilize the versatility of quantum bits, or qubits. Qubits are not limited to a single state; they can be set to one or the other, simultaneously both or even states in between.
Modern asymmetric cryptography relies upon the fact that integer factorization on digital computers is computationally infeasible when using large numbers. However, quantum computers have the capability of finding prime factors of large numbers using Shor’s algorithm, a quantum algorithm which makes use of the increased potential computing power of quantum computers. This capability can be used to defeat standard cryptographic systems, including the Diffie-Hellman protocol, other discrete logarithm based cryptographic systems and elliptic curve cryptography.
This new development creates the need to develop new cryptographic algorithms that are resistant to quantum computing. NIST is heading off a community effort in the shape of a competition in an attempt to meet that demand for new algorithms, similar to the way SHA-3 was developed and standardized.
The community competition approach has proven itself to be effective over time because all of the best standard cryptographic algorithms are open-source and must meet the basic criteria as outlined in Kerckhoffs’s principle. Closed source projects are often less secure because they are subject to vulnerabilities unnoticed by the original authors. Open-source systems, on the other hand, must undergo rigorous testing before the eyes of many of the most intelligent developers and mathematicians. This is why our greatest hope for new and quantum computer resistant crypto-systems is the collective internet community and academia.
For though quantum computers are currently rare and accessible to few, it’s only a matter of time before they become more common, until all cryptographic algorithms once thought to be are no longer secure.