Can somebody explain this ?

The entire blockchain for both systems is determined by fewer than 20 mining entities [4]. While traditional Byzantine quorum systems operate in a different model than Bitcoin and Ethereum, a Byzantine quorum system with 20 nodes would be more decentralized than Bitcoin or Ethereum with significantly fewer resource costs. Of course, the design of a quorum protocol that provides open participation, while fairly selecting 20 nodes to sequence transactions, is non-trivial.

Where is the question ?

We're gonna need a question mark somewhere. Ctrl+F failed.

Yes, dark chocolate is healthier than white chocolate because it contains less sugar and a larger cacao percentage. Hope that answers your question

Jack@ said:

Yes, dark chocolate is healthier than white chocolate because it contains less sugar and a larger cacao percentage. Hope that answers your question

Click to expand...

you killed it!!

I think OP's question is what does the block of text mean?

depends on what they mean by the word "entities". Perhaps they mean to say that the majority of coins are mined by a few big groups. A link to the original source would be helpful.

I think he wanna ask what is the meaning of byzantine quorum system

er, Ill have a go at answering.

Bitcoin (well Proof of work) attempts solve the Byzantium generals problem where a network needs to arrive at a consensus by making participants use up a set amount of CPU power to be able to contribute. Satoshi explains it better than I can here.

Where this fails is in the event of a 51% attack where someone gains more than half the hashing power of the whole network and is able to push through their own version of "consensus". Part of the Ethereum Byzantium update brings failure or success receipts for nodes to tell if a transaction succeeded or not. Meaning light clients (ie ones who have not downloaded the whole massive chain - eg a mobile app) can tell if a specific transaction is valid or not without relying on depth of linked hashes before it. An important needed step before switching to proof of stake...if ETH eventually gets there.

The article that @partyush copy and pasted from seems to be saying that both Bitcoin and Ethereum are becoming too centralised due to mining farms & pools. Meaning that they are not really Byzantium fault tolerant. What they seem to be saying is a smaller network with only 20 nodes could be more resistant to this type of attack than the current network distribution. But they also acknowledge that deciding which nodes to "trust" and make up that 20 has not been solved yet. The partial solution they propose doesn't half sound a bit like watchtowers on Lightening Network but I didn't go as far as looking at the paper the article is referencing. At least that's what I get from it... Anyone else?

Also, AFAIK at least one of the authors has been linked to bcash and footnote #3 is a bit odd so Im not sure how neutral it is.

But that said, there has been a few times when certain pools had more than 51% of the bitcoin hash rate. Its feasible that they could have taken control of the chain then - but thankfully they didnt. As the overall hash rate goes up the harder 51% gets. BTC.com (so Bitmain) are currently at 24% with the largest percentage but that's a good way off 51%. This kind of attack on verge or bitcoin gold is one thing but some "bad actor" suddenly coming along with over 15,000,000 TH/s against bitcoin seems very unlikely with current technology.

Garlic Bread?