Delegated proof-of-stake (DPoS) is a fundamentally different consensus protocol from proof-of-work (PoW). The difference between the two presents itself in the kind of freedom they promote; while DPoS is freedom under a benign master, PoW is freedom from domination.
What Is Freedom?
Freedom can be understood in negative or positive terms, thanks to Isaiah Berlin. Negative freedom, according to Berlin, is the absence of interference or constraints. Positive freedom, by contrast, is having the capacity to do something to realize one’s potential. Negative freedom is also known as liberal freedom. According to the classical political philosophers that Berlin followed (Hobbes, for instance), one can enjoy freedom only when free from interference. It does not matter if there is a master who can arbitrarily interfere. If there are multiple doors to choose from and gatekeepers at each door, liberals argue that freedom means choosing and going through a door without interference. Keep this analogy in mind.
I’ve argued elsewhere that bitcoin freedom comprises both negative and positive freedom. Quentin Skinner defines this new conception of freedom as neo-Roman, and Phillip Pettit coins the term republican freedom as non-domination. With a minuscule difference, they both argue the same idea of freedom. Freedom as non-domination is negative because it promises freedom from domination (arbitrary interference) and positive freedom because it promotes practices to realize its potential. However, the most distinct aspect of freedom as non-domination is the ability to control power. Following the door analogy above, there can be gatekeepers, but citizens must control their behavior to practice their freedom of choosing and going through a door. Merely an absence of interference does not mean we are free because an arbitrary decision of a gatekeeper might take our freedom away. Being vigilant to check and control gatekeepers’ power is critical in freedom as non-domination.
Why PoW Is Essential For Freedom As Non-Domination
Freedom and decentralization are indispensable from each other because freedom can be possible only under decentralized power. Power needs to be broken up to secure liberty. A similar argument by Montesquieu in 1748 established one of the most critical pillars of democratic government: separation of power (see my short essay). For citizens to be free, branches of the government have to be separated so that they check and balance each other. Bitcoin, in this respect, promotes freedom as non-domination through its PoW consensus mechanism because a vast number of independent nodes to validate transactions and create new blocks is critical in dispersing the power for blockchain. If this power is concentrated in a few nodes, then the chances of arbitrary action of a blockchain would be easier, hence risks the freedom it promotes.
DPoS: Freedom Under A Benign Master
Delegated proof-of-stake is a consensus protocol that disperses the power to validate transactions and create new blocks to a few nodes. In a DPoS protocol, a few nodes take turns to produce blocks and validate transactions. In other words, the freedom of DPoS users is controlled by a few node operators. Although one could argue that those nodes are alternating between doing the work and are not functioning in a centralized fashion, thousands of Bitcoin nodes disseminated worldwide are absolutely more decentralized and secure. As discussed above, the more decentralized, the more security for freedom can be promoted.
Can we be free under a benign master? No! Freedom is not freedom unless there is some guarantee for maintaining that freedom for tomorrow. The master(s) of the blockchain run on the DPoS consensus mechanism can be good and benign today. They can “give” freedom to the users. Yet, the checks and balances to the power of the masters are much less vigorous than in Bitcoin. The freedom that is given can be taken away. For this reason, a mere possibility of interference creates domination. Bitcoin freedom, on the other hand, is freedom from domination. There are no “benevolent” gatekeepers who can change their minds in the future on a whim. The difference, in a nutshell, is between a benign master who gives freedom and an empowered citizenry of nodes that takes it.
This is a guest post by Burak Tamaç. Opinions expressed are entirely their own and do not necessarily reflect those of BTC Inc or Bitcoin Magazine.