Some countries, including the US, are exploring a new type of money that can be spent only electronically.

BibTeX Citation: @misc{dryja2020lower, title={A Lower Bound for Byzantine Agreement and Consensus for Adaptive Adversaries using VDFs}, author={Thaddeus Dryja and Quanquan C. Liu and Neha Narula}, year={2020}, eprint={2004.01939}, archivePrefix={arXiv}, primaryClass={cs.DC}

Cline, D., Narula, N., & Dryja, T. (2020). ClockWork: An Exchange Protocol for Proofs of Non Front-Running. Stanford, CA: The Stanford Blockchain Conference.