Privacy, Blockchain, Mixnet, Elixxir, Nym 101.
against powerful adversaries like the NSA. References: [1] “Untraceable electronic mail, return addresses, and digital pseudonyms”, D. L. Chaum; Communications of the ACM; Link [2] “The Loopix Anonymity System”, A. M. Piotrowska, J. Hayes, T. Elahi, S. Meiser and G. Danezis; USENIX Security