Moore's law describes an important trend in the history of computer hardware: that the number of transistors that can be inexpensively placed on an integrated circuit is increasing exponentially, doubling approximately every two years. The trend has continued for more than half a century and is not expected to stop for another decade at least and perhaps much longer.

Many publications recommending key lengths of cryptographic primitives take into account the historical rate of computational improvement which is based on Moore’s law to determine how long a key length might be secure [see here, here, and here].

This type of analysis attempts to extrapolate future performance from the past rate of development. This type of approach cannot take into account disruptive advances in science and technology. For example according to a press announcement “a team of Michigan Technological University researchers led by physicist Ranjit Pati have developed a model to explain the mechanism behind the single molecular switch, widely considered to be computing's Holy Grail. If worked out experimentally, the model could help explode Moore's Law and revolutionize computing technology.”

Another example is that it is not known at what time computers will have greater computational ability than humans – or alternatively at what time computer enhanced humans will significantly exceed our current intelligence levels. One or more abrupt advances in computing power may occur as a result of AI.

The situation is worse when we attempt to consider the interaction between Moore's law and quantum computers. Unfortunately it is not possible to project how fast quantum computing power might grow in the next year, five years or 20 years because, according to Prof. Scott Aaronson of MIT, “there is currently no analogue of Moore’s law for quantum computing”.  In theory the performance of some quantum computers could rapidly increase in a short period of time, particularly if the model can leverage the already mature semiconductor industry.

What is needed is a conservative method to address the issue of Moore's law, the anticipated arrival of code-breaking quantum computers, and the unknown rate of improvement of said computers.

Click here to read about Synaptic Labs' proposal to address these issues.