The earliest research was published in 2012 and started to take off with the first Bitcoin bubble of 2013. Since then, the research landscape has expanded rapidly, with every discipline and nearly every topic represented. For example, the Blockchain Research Network bibliography contains over 2400 items. At the same time, anecdotally, the quality of research has risen significantly too.
This short description is an attempt to detail the breadth and depth of cryptocurrency and blockchain research. It will be frequently updated as the field grows and the landscape changes. I invite contributions and feedback.
See also Research Centers, Labs, and Classes for further information about active research and educational offerings.