OK, gotta quote David Chaum from "Untraceable Electronic Mail, Return Addresses, and Digital Pseudonyms", published in 1981:[0]
> This paper presents a solution to the traffic analysis problem that is based on public key cryptography. Baran has solved the traffic analysis problem for networks, but requires each participant to trust a common authority. In contrast, systems based on the solution advanced here can be compromised only by subversion or conspiracy of all of a set of authorities.
> This paper presents a solution to the traffic analysis problem that is based on public key cryptography. Baran has solved the traffic analysis problem for networks, but requires each participant to trust a common authority. In contrast, systems based on the solution advanced here can be compromised only by subversion or conspiracy of all of a set of authorities.
0) https://www.cs.utexas.edu/~shmat/courses/cs395t_fall04/chaum...