When Blockchains are spoken of, almost always decentralization is the next word that follows, however there remains some blockchains that have not been decentralized yet, despite having some that promised decentralization upon their birth.
- NEO:A Chinese blockchain, meant to be decentralized months back, but remains under the control of the company. And that gives them the power to reset the network incas the Delegated Byzantine Fault Tolerance system fails to achieve consensus.
- IOTA: Is technically a DAG more than it is a conventional blockchain. Though it seems likely that NEO will reach a stage of decentralization someday, it is doubtful whether IOTA can work without a central coordinator to take care of things the moment there’s a glitch or two.
- Cardano: Cardano plans to use an algorithm called Ouroboros and so for the past 12 months or there about, the cryptocurrency has been heavily controlled by a central authority.
- EOS: Uses an algorithm that places the control in the hands of a few; about 21 block validators-trusted validators such as Bitfinex. About two thirds majority is needed to reach a consensus if any change is to be implemented.
One thing though, we need to bear in mind is that all cryptocurrencies start out as centralized entities, and what defines their being called cryptocurrencies is the willingness for the central power to relinquish the control.