Homework on Soft and Hard Forks - Questions

[Brett_Schor]

1. A soft fork results when updates to the consensus protocol make the ruleset more narrow (previously valid blocks become invalid). As long as 50% of the nodes update to the new version, a fork is avoided (all the nodes that didn’t update will be outpaced by the nodes that did update, leading to a convergence of one chain). A hard fork results when updates to the consensus protocol expand the rule set (previously invalid blocks become valid). This can divide the community and lead to the emergence of two separate chains.

2. A hard fork may be desirable in cases where the community is strongly divided over the update and wants to reach a clear/decisive outcome with two different chains and two different rule sets (miners are forced to pick a side)

3. Risks for a hard fork include political fractures within a community, the emergence of a second chain, and a division of hashpower (which can weaken the security of both chains)

[jgentry]

1. A soft fork makes previously valid blocks invalid, whereas a hard fork makes previously invalid blocks valid.

2. You would do a hard fork for these reasons: 1) to create a clear, democratic update; and 2) develop a new currency.

3. Some of the risks with performing a hard fork are splitting the blockchain, splitting the community, and splitting the hash power. Splitting the hash power reduces security.

[Yovan]

@ivan

What is the difference between a softfork and a hardfork?

Hardfork is expansion of ruleset, while Softfork is contraction of ruleset.
HF splits the chain, SF has no spit chain.

@ivan

What are some of the reasons why you would do a hardfork?

To change the consenses ruleset in order to validate the block.

@ivan

What are some of the risks with performing a hardfork?

Hash power, community and the chain are split.

[TrevPeter]

1. Increase block size.
2. Transaction malleability.
3. Possibility of second layer protocols .(Base of Lightning Network)
4. No, it is a soft fork.

[bobchain]

1. What is the difference between a softfork and a hard fork?
   A soft fork makes valid blocks invalid and a hard fork makes invalid blocks valid.
2. What are some of the reasons why you would do a hard fork?
   Correcting important security risk found in older version of the software,
   add new functions, reverse a tx’s due to a hack.
3. What are some of the risks with performing a hardfork?
   It splits the community, splits the chain. As I understand it, If a large enough percentage of the community decides that they want to continue using the old rules then the chain will split, resulting in two separate currencies

[FrankB]

1. A hard fork is resultant of an update that renders valid certain blocks that were previously invalid (and that, presumably, does not render invalid any previously valid blocks, as otherwise a fork could be hard and soft simultaneously, as explained in my pertinent discussion post), and a soft fork, conversely, is resultant of an update that renders invalid certain blocks that previously were valid (and that, presumably, does not render valid any previously invalid blocks).
2. If you wish to increase the block size because you want to increase the processing speed of the blockchain, then your motivation for introducing that change is not (or not necessarily) the creation of a hard fork but simply and soley the bringing-about of an increase in the processing speed. So it seems to me that hard forks are implemented not (or not necessarily) because someone likes hard forks better than soft forks but because someone wants to implement an update that happens to be expansive in nature and therefore results in a hard fork. So when you ask for reasons for creating a hard fork, it seems to me, your question is aimed at the motivation for implementing an update that happens to be expansive in nature rather than the motivation for creating a certain type of fork. It appears unnatural for anyone to want to create a hard fork—in contradistinction to a soft fork—but it does appear perfectly natural, for instance, for someone to desire to increase processing speed by increasing block size. In other words, the reasons for a hard fork have to be looked at on a case by case technical basis and will commonly not be reasons for the generation of a certain type of fork but for the bringing-about of a certain type of technical improvement that so happens to result in the creation of a certain type of fork.
3. The main risks, so far as I can tell, are a) the splitting of the creative potential of the community of developers (as the hard forks splits that community into two competing parts) and b) the reduction in blockchain security due to the reduction in hash power (because the network of miners will be split into two groups). Moreover, the break-up of the community may also be accompanied by unpleasant personal animosities. So there is a human social and psychological risk as well (and maybe this latter risk is in fact the greatest risk when viewed from a higher, spiritual perspective).

[blue]

1. softfork is when a previous valid block becomes invalid due to a tightening of the consensus rules. Hardfork is when that update makes a previously invalid block valid… an expansion of the rules.
2. when you want/need a clear new set of rules and therefore a new community, and it’s democratic
3. your chain becomes split, as well as the community and the hash power.

[Aaron_C]

1. What is the difference between a softfork and a hardfork?
   Softfork = makes a previously valid block invalid - decreases validity
   Hardfork = makes a previously invalid block valid - increases validity

2. What are some of the reasons why you would do a hardfork?
   To correct security risks, add new functionality, changes to community consensus.

3. What are some of the risks with performing a hardfork?
   Splits the hash power and community.

[MasterofCoin]

1. A hardfork is an expansion of the of the ruleset that governs consensus for block creation while a softfork is and contraction of said rulesets.

2. It is more democratic - If you don’t agree with the current implementation of the software you still have the option for self determination i.e the freedom to walk away with like minded community members and do something new. Also it may be needed for critical software updates.

3. The splitting of the community and the battle for legitimacy over branding and other aspects of identity.

[Andreas_C]

1. What is the difference between a softfork and a hardfork?
   -> Softforks are tightening the rule set and hard fors are expanding the rule set. Softforks are making previously valid blocks invalid, Hardforks are the opposite.

2. What are some of the reasons why you would do a hard fork?
   to improve security, to improve speed, use cases for the blockchain.

3. What are some of the risks with performing a hard fork?
   community will not follow, splits hashrate (less security)

[Lunasea]

1. A Hard Fork makes previously invalid blocks valid and leads to a chain-split. A Soft Fork makes previously valid blocks invalid and doesn’t split the chain, if more than 50% of the miners implement the update.
2. A Hard Fork expands the consensus rules.
3. A Hard Fork splits the chain, divides the community and reduces the hash power. All this leads to a blockchain that is less secure.

[Fabrice]

@BrianR

But is it not fair to say that that the emergence of hard fork will generally produce more stale blocks, as nodes have not yet upgraded to the new version of the protocol software continue to produce blocks that will be invalid?

Stale blocks are blocks that were valid, but dropped from the blockchain. In a hard fork, there will be 2 different blockchains with different rules. So a miner on blockchain A can’t mine a valid block on blockchain B. After a hardfork with a split, they become 2 totally different networks.

@BrianR

I don’t know what a node is, I am just trying to buy something with this new strange currency) had not updated to the latest set of rules.

A node is just a computer that has bitcoin software installed with a full copy of the blockchain and validating every transaction and block that happens on the bitcoin network.

@BrianR

By the way I work for a Belgian company and in normal times I am there quite often

Nice, I’m Belgian. Wich company do you work for?

[Mauro]

@TrevPeter

2. It is more clear and democratic.

Sure, but can you list any examples why we would need a hard fork?

[Mauro]

@Marc-C

3. What are some of the risks with performing a hardfork? Hardforks will spit the chain, split the community, create a new currency, hash power splits as miners go to new chain and this can lower security

@AliasFresh

3. What are some of the risks with performing a hardfork?

A hard fork splits the chain, splits the community and affects the hash. All of these will weaken the project. (Particularly the hash rate as this effects the security and efficiency of the chain)

All of these have negative potential but non more than splitting the community.

A deep enough split can kill a project.

RIP

Hard fork can cause a chain split, but it does not have to. If everyone agrees or everyone disagrees then there will be no chain split, new currency or hash power split. That’s why we say doing a hard fork is risky.

[Mauro]

@yestome

1. Hard forks expand the rule set while soft forks contract the set of rules. Hard forks will always lead to a split of the chain as part of the community will decide not to comply with the new set of rules and continue working on their now forked chain to create a new currency (BitcoinCash, BitcoinSV, etc.). Soft forks will initially split the chain into 2 accepted chains, and over time the chain that adds new blocks more quickly by adding more PoW will become the accepted chain and the other chain will be dropped, the split will disappear.

@Lunasea

1. A Hard Fork makes previously invalid blocks valid and leads to a chain-split. A Soft Fork makes previously valid blocks invalid and doesn’t split the chain, if more than 50% of the miners implement the update.

Hard fork can cause a chain split, but they don’t have to. If everyone updates the chain goes on with the new rules, and if everyone declines the chain goes on like nothing happened. But in most cases some will update and some won’t. This will cause the chain to split. When it comes to soft forks, there is no chain split at all. A soft fork either gets adopted or it dies out.

[Mauro]

@Brett_Schor

1. A soft fork results when updates to the consensus protocol make the ruleset more narrow (previously valid blocks become invalid). As long as 50% of the nodes update to the new version, a fork is avoided (all the nodes that didn’t update will be outpaced by the nodes that did update, leading to a convergence of one chain)

If more than 50% of people accept the soft fork, we can say it got adopted. If less than the 50% of nodes update then the update failed. Since soft forks are backwards compatible there can never be a chain split.

[Mauro]

@bobchain

2. What are some of the reasons why you would do a hard fork?
   Correcting important security risk found in older version of the software,
   add new functions, reverse a tx’s due to a hack.

“reverse a tx’s due to a hack.” This is a good example because not everyone will agree on it. Some think the blockchain should never change, even if an attack occurs, while some would want to have an exception. Here is an interesting read: https://coincentral.com/ethereum-classic-vs-ethereum/

[Mauro]

@Lunasea

2.A Hard Fork expands the consensus rules.

Can you list some of examples of why we would want to do a hard fork?

[bobchain]

Thank You Mr.Mauro, I read that article and it gave me a great deal of info and understanding about something I had heard before but didn’t understand to this extent.

[Zee2020]

• What is the difference between a soft fork and a hard fork?

A soft fork decreases the block size that can be accepted. A hard fork increases the block size that can be accepted into the network.

• What are some of the reasons why you would do a hard fork?

If you wanted to create new currency then a hard fork would be one way of achieving this. The desire for a new currency can be the result of disagreement within the community. A hard fork in this case would create another chain where a different rule set can be followed.

• What are some of the risks with performing a hard fork?

A split in the chain, leading to a loss of hash power, and a split in the community.