Disclaimer, this list is ordered in my own personal opinion based on how secure, fast and scalable each protocol is. All of them have their own strengths & weaknesses with there being no clear "best" protocol.
6. Nonconsensus protocol
Cryptocurrencies using this: Tether, Ripple, Stellar
Tether is the coin that mainly uses this, what this means is that there is no form of decentralization at all. All the coins and/or tokens can be controlled by a central body or admin. In Tether's case it's Tether. This goes completely against one of the main ideas of crypto meaning that it's no better than using the dollars with a bank, other than slightly quicker trades as the funds are already on an exchange.
5. Proof-of-Work
Cryptocurrencies using this: Ethereum, Bitcoin, Litecoin
The oldest protocol in the cryosphere. The most popular user of this is Bitcoin, as well as most of the older coins such as DOGE, ETH and LTC. What this means that there are computers that goes through all previous transactions as well as process any new ones that have taken place, once all the computers on the network have gone through and verified them there is a new block created that has the full LEDGER of all the transactions. This means that transaction processing gets harder over time. Miners get rewarded by some of the new minted tokens from the block creation and/or the transfer fee. This does come with som drawback as this requires an insane amount of electricity.
4. Proof-of-Stake
Cryptocurrencies using this: Cardano, Solana, BINANCE coin
Existing coins are used as a means of voting and verifying new block creation. Same process as before where most of the miners (validators in this case) have to agree on the state of the freshly created block. This doesn't require as much power and is easier for users to get into and start earning a passive income. There are several methods of performing this but they are mostly grouped together here as they all perform the same, more or less.
How validators are chosen varies depending on what type of proof-of-stake is used. General idea that most blockchains use is that they vary the different validators to prevent one validator gathering too much voting power and possibly causing a 51% attack. This can be chosen at random, in order or through a selection process.
3. GRANDPA & BABE protocol
Cryptocurrencies using this: Polkadot, Kusama
Polkadot's native protocols, functioning similarily to proof-of-stake. The BABE has a random lottery where different validators are chosen, in case there is no validator it goes over to a round-robin protocol to prevent any block from being blockless. It also selects several validators for one block and has these validators rush to be the first to reach the majority of the network, promoting speed in the block creation.
Secondly GRANDPA comes into play, as the previous protocol would rampant alone. There will be several chains consisting at once as the several validators work to become the most widely recognized chain. GRANDPA identifies this chain and solidifies it as the finalized chain causing all the other running chains to be null. The BABE protocol starts to produce new blocks on this new finalized chain and the process starts over.
2. IOTA protocol
Cryptocurrencies using this: Iota
A unique and highly scalable protocol that basically uses part of the trader's processing power. Require no mining or staking. This means that the more users the network has the higher TPS it has, creating an insane and unparalleled TPS. The one thing holding this back is that in order to 51% attack the system you only need to overpower 51% of the current transactions taking place. This causes security issues that the fees in other networks solve. Speed or security? If the security flaw gets fixed, this protocol would be contendor for being, if not, the best protocol in cryptocurrency. Would IOTA get around this I would be an avid supporter as it would compete much more strongly with the coins higher up on the marketcap such as Solana.
1. Proof-of-History
Cryptocurrencies using this: Solana
This is Solana's secondary protocol they utilize apart from their proof-of-stake, and it is supplementary. What this does is that it doesn't require the blockchain or validators to trust timestamps of when validating transactions. Instead, there is a cryptographical hash function that calculates the time between each event taking place allowing nodes to process events after they happen and publicly verify them. It basically functions as an internal clock for the blockchain as any and all outside sources for time can't be trusted as they can be manipulated. Essentially this means that the more nodes there are in a network the quicker it becomes thanks to this clock, basically the opposite to Ethereum.
Was there any blockchain protocol that I should've included in the list? Feel free to drop your thoughts in the comments below!
