Do Blockchain Technologies Make Us Safer? Do Cryptocurrencies Necessarily Make Us Less Safe?

This essay is based on a presentation made on January' 24,2020 at the invitation of the Texas Journal of International Law and the Strauss Center for National Security at the University of Texas. That presentation focused on the two questions mentioned in the title of this essay - Do Blockchain Technologies Make Us Safer? And Do Cryptocurrencies Necessarily Make Us Less Safe? The essay presents answers to the two questions: "yes" and "probably yes." This essay begins with some level-setting on different types of blockchain technologies and of cryptocurrencies, and gives some background materials on global and national responses to certain cryptocurrencies, such as El Petro sponsored by Venezuela's PDVSA and Facebook's Libra. [ABSTRACT FROM AUTHOR]