What you talk about already exists in many varieties and is centralized, any fiat currency or credits issued by a company fit what you just described.
Countries could use the Blockchain technology to track EVERY SINGLE thing you buy via the blockchain..
The ablity to oppress people with the blockchain is a very real and horrible thing.
I have a feeling before I die there will be wars fought over this(There must be or freedom dies)... civil ones... when govs attempt to implment this on their people under the idea of "protceting you from terrorism"