A large family 60,000 BCH stolen posts for help caused by the eyeball effect once again let attention bCH, this time, people are no longer concerned about the "strong donation" of the political issue, but "rolling checkpoint" this technical issue. Of course, the question layer by layer recursive, always involves the most core design philosophy problem -BCH enables rolling checkpoints, is it an angel? Or the devil?
Checkpoint concerns caused by theft
Before you say checkpoint, look at the event itself.
A Bitcoin giant posted on Reddit that he had lost 60,000 BCS (in addition to 1,500 BTCs, but he was more concerned about the 60,000 BCs) and wanted to pay the miners to help him recover them. The post was accompanied by a digital signature that proved to be true and valid.
The story is so simple, as to who the big man, the background, BTC and BCH and how to lose, with this article is not much, interested friends can search for themselves, after all, about this incident report, the industry is also a worldwide.
More concerned about this giant whale, why would he think of using the method of "heavy gold miners" to recover his lost BCH? What do miners have to do to "recover" the stolen BCH? Enter the industry more long, some people who know about technology know, that is the legend of the big killer, double flower! Collection calculation force, let the current chain void, after the theft of the block height to restart the generation of blocks, make a new "longest chain" can be.
While double flowers can harm the network, in some special moments, you can also use "good-faith double flower" to protect the network. There was a precedent in The history of BCH, last May in the hard fork process, the network because of THE BUG was hacked, several large mines together to pack 10 empty blocks, resulting in the hacker's attack invalid. After 10 blocks, the network is protected because the rolling checkpoint is no longer possible to roll back to 10 blocks.
And this giant whale, unfortunately, the time of posting has passed 10 blocks of time, no double flowers and rollback can be carried out ...
Thus, the various media divided into two factions, one quite BCH, support the rolling checkpoint, one faction against, think that the rolling checkpoint is a "ridiculous" design, this article to focus on you to talk about this "rolling checkpoint" of the past, and comb the core views of the two factions.
02 The past life of the Rolling Checkpoint
1. What is a checkpoint
To know about rolling checkpoints, you need to know what checkpoints are.
Checkpoint, as defined in Bitcoin academic words, is: "The hash of a block that specifies the height of a block must be equal to a hash."
To put it bluntly, by recognizing that the block of the checkpoint is a legitimate block, this height can be avoided by other forces of all the previous blocks, in particular, to avoid being attacked by a 51% advantage calculation block reorganizing blocks.
In other words, the node that executes the checkpoint identifies the specified block, and then determines all the blocks before the block, and the principle that the longest chain previously defined by Nakamoto is a valid chain, "variation" becomes "the longest chain containing the checkpoint is the effective chain." "
Nakamoto invented checkpoint sits because the network was still very fragile at the beginning of the digital currency, and for security reasons, Nakamoto joined the checkpoint design to protect so many successful effective blocks in the moment of some major upgrades or patches. Essentially, the checkpoint is to sacrifice partial decentralization for network stability and reliability.
In the early days of Litecoin, Charlie Lee also used checkpoints to prevent 51% of attacks, according to his original words: "Checkpoints are a centralized feature because it depends on the developer to decide which is the right chain." This makes sense for the beginning of the digital currency. "
2. Rolling checkpoints
Having finished the checkpoint, let's take a look at the BCH's rolling checkpoint.
On November 21, 19, BCH officially tweeted"Bitcoin AB C 0.18.5 version is online. Rolling blocks "checkpoints" have been added to this edition as deep reorganization protection to ensure that transactions are confirmed as immutable, thus protecting users, businesses and trading platforms. "I's going
At that time , during the War of BCH and BSV , BCH's move caused an uproar in the mine circle . Before a large V in the calculation of the pre-war analysis of various scenes, including front al-stop, full-scale war, guerrilla warfare and so on all failed. Because the appearance of rolling checkpoints directly results in the block being determined to be finally valid as soon as ten confirmations are received. That is, even if the replacement chain has more work, as long as it conflicts with checkpoints, the node will not switch to the more workload chain, resulting in the "longest chain" principle before Bitcoin, almost completely invalidated.
Interestingly, the BCH community and the BSV community are two completely different interpretations in this matter.
In the view of the BCH side , without rolling checkpoints , the two sides will likely last for months or even longer , burning every day in real money . In the long run, no matter which side achieves the ultimate victory, it will be a thousand enemies, self-inflicted eight hundred tragic victory, even extreme points, both chains are finished. In so doing, it is essentially the best situation for peace, for everyone to abandon war and develop oursown.
In BSV's view, this is a clear act of war avoidance, is a "encouragement" performance. According to Nakamoto's design concept, when the concept is completely irreconcilable, it should be used to vote, to fight for the longest chain, the right to win. The design of the rolling checkpoint completely violates the design principles of Nakamoto's longest chain, seriously undermines PoW's economic incentive model, and is completely "messy".
03 Benefits of Rolling Checkpoints - Positive Viewpoint
Putting aside the calculation power war to avoid war or not, the rolling checkpoint will certainly bring a lot of impact on BCH, take this large-scale currency loss incident as an example.
What is the nature of cryptocurrencies? It's freedom, a cryptopunk freedom. Take Bitcoin, for example, when and where you want to transfer money to what kind of country and what kind of people, it is your freedom, no one can stop your freedom.
That's why, for the first time, Bitcoin has technically guaranteed "the sacrosanct ness of private property," the old cat said in his sermon.
What BCH is going to do now is to further expand the concept - BCH for the first time from a technical point of view to ensure that "Trade 10 confirms sacrosanctness".
Why so, because in essence, BTC is able to recover coins through miners' double flowers, which is why CZ considered this approach after the last time the coins were stolen.
And on the BCH side, more than 10 confirmation is absolutely not possible, unless you can handle the head pool at the same time, the development team, let hundreds of exchanges around the world and the vast number of BCH users, develop a new version and everyone switch over, from this point of view, this is the real decentralization.
And back to what we just said about "freedom", but where Bitcoin or BCH is rolling back a transaction because of some exceptions, if it happens once, perhaps the "Freedom Tower" will collapse. Historically, Ethereum's "rollback" ofthe DAO incident caused a blow to the entire "Code is Law" encryption community at the time, and if this happened to the blockchain's ancestors, or totem's Bitcoin, the damage must have been far greater than the DAO incident of that year. BCH's rolling checkpoints can be said to have completely avoided this possibility.
04 The Bad Side of The Rolling Checkpoint - Counter-View
Aside from the calculation war, while BCH's rolling checkpoints seem to protect the safety of users' property, by its very nature, this is no longer PoW.
What is Bitcoin's most disruptive and colorful design? Or what's the greatness of Bitcoin compared to the previous failed egold e-cash?
In fact, it is very simple, is that Bitcoin solves the case without trusting a third party, the two parties can directly secure and effective transactions, the most important of which is to solve the case of no trust in the third party "double flower" and Byzantine General problem.
How did you solve it?
1.Timestamps - Timestamps are at the heart of Bitcoin, so much so that Mr Nakamoto calls the Bitcoin system a "distributed and secure timestamp server."
"The timestamp server adds a timestamp to the hash calculation of a block's data and publishes the hash calculation on a large scale, as it is published in a newspaper or news network. Obviously, timestamps confirm that these data must exist at this particular time, and only then can the hash calculation sit off".
2. PoW - In this distributed system, who will cover the timestamp, is through the workload proof (PoW), who can pre-empt the hash values that fall within a range, who can stamp the timestamp. Next, how does this timestamp get a consensus? Rely on the principle of the longest chain, that is, the decision of most computing forces. The work proof plus the longest chain principle is also known as the Nakamoto Consensus, which is the most central part of all blockchain systems, and its essence is to achieve distributed timestamp services.
The earliest people asked Nakamoto about the longest chain in the forum: "What if the "bad guys" have more computing power than "good guys"?" "
Mr Nakamoto's answer is:
"First of all, it requires a single "bad guy" to have more computing power than all the "good guys" are calculated; second, even if a single "bad guy" has a greater calculation, all he can do is spend his own money, and he needs to spend the money by buying something (now he can trade on an exchange) and then receive it. after the goods, the money was respent through the attack network. Such an attack may not be cost-effective for an attacker, if it is better to mine. "
Looking back on BCH, now BCH has designed a checkpoint every 10 blocks, that is, as long as the honest miners can't beat the villain in 10 blocks, the villain's record will remain on the chain forever. This is not Bitcoin's original intention at all. Not even PoW anymore. Bitcoin was originally designed to keep the villain's record on the chain as long as the villain's calculation spree doesnot beat the power of honest miners.
Deeper, is cryptocurrencies, or the nature of blockchain, so-called "cryptopunk freedom"? The villains represented by BSV clearly don't see it that way, and in their view, the true nature of Code is Code, Law is Law, and the monetary is not this "freedom of anarchy" but trust. A global trusted ledger driven by technology and economic incentives. The rolling checkpoint, while reinforcing the Code Is Law brand, also reinforces centralization (referring to the previous BCH upgrade, the mine pool joined forces to hit 10 empty blocks to launch a 51% attack to defend the BCH paragraph).
What do you think of BCH's 10-block rolling checkpoint design? Is it "technically guaranteed to confirm the sacrosanct ness of trading 10" or "a centralmeans that undermines the principle of the longest pow chain"
