If you prefer to have a immutable database that is anchored to a blockchain, rather then a permissioned blockchain, I suggest looking at the Politeia toolkit. Time stamping the sum content of any data repository makes it censorship resistant.
This article is assumes that attacking a blockchain would be just the classical 51% attack scenario of bitcoin. Innovation from coins such as Decred show an evolution in blockchain technology that makes a 51% attack exceedingly more challenging to pull off.
"Apples to apples, Decred is 20x more expensive to attack than Bitcoin"
https://blog.usejournal.com/apples-to-apples-decred-is-20x-m...
Bitcoin demonstrated that is is possible to dis-intermediate the storage and transmission of value, an area that is the mainstay of the banking industry.
Ethereum allows for open experimentation, and has brought about the emergence of arbitrary tokens.
Decred has demonstrated that is it possible to dis-intermediate the process of political decision-making for a cryptocurrency.
zkc, zero knowledge communications, was released today. It is just the first release, and a minimal tool with minimal features, but its exactly the solid foundation I have been waiting for.
"zkc is a blending of what we consider to be the best parts of both of these projects, Signal and Pond"
"The UI is text-based and emulates the appearance of irssi, in order to keep UI-related complexity low and avoid large GUI toolkits as a dependency."
"intended to provide the highest level of communications security balanced with minimal complexity in its code, configuration and usage."
https://blog.decred.org/2017/10/25/Politeia/ https://github.com/decred/politeia