Homework on Soft and Hard Forks - Questions

[sherlock]

1. Softfork: previous valid block becomes unvalid, Hardfork: previous unvalid block becomes valid

2. democratic updates and to create new currencies

3. split of the hash power & community that not agree the changes

[Fabrice]

@TeresaK

Therefore, with a hard fork is it correct to state that if the hard fork was to fix a security problem like Segwit, then the network can either choose to adopt the fork or remain on the old chain? Is it also correct to state that a hard fork could also be the creation of another rule which creates another currency?

Segwit was a soft fork, it changes some consensus rules. Fixed mallebility issue, put signatures in different data structure. Segwit transaction still follow the old rules before the soft fork.(backwards compatible) Because the blocks without signatures of Segwit tx’s is Not higher than 1MB. So it can operate on the same blockchain

It’s uses a different way to calculate blocksize. (in vbyte)
With weight units. (4 weight units is 1 vbyte)
(each weight unit represents 1/4,000,000th of the maximum size of a block.

@TeresaK

also correct to state that a hard fork could also be the creation of another rule which creates another currency?

Yes, in a hard fork, everyone needs to update, because new blocks will not be valid under the old rules (before the hardfork) because if a small community of miners and users wanna keep on the other chain and consensus rules , there will be 2 blockchains (with same history since the fork) and 2 different currencies having different chain and consensus

[Timothy]

1. Softfork makes previous valid blocks invalid and needs majority of the hash power to update, but hardfork makes previous invalid blocks valid and needs 100% of the network to update
2. If you want to add some extra rules or change them
3. Splitting the community and reducing a hash power means reducing a security of the network

[TeresaK]

Thanks Fabrice. One final question. For those users who have not adopted the soft fork to Segwit; does that mean that they are using the old rules which means security is compromised? i.e. the transaction ID can be altered? Surely all users would want to use the enhanced security of Segwit.

[Cupid]

a soft fork is an update of the consensus that makes previously valid blocks invalid a hard fork is just the opposite

the creation of a new coin consensus rules fixing errors

a hard fork will split the community of miners and thereby considerable hash power and after reduction

[KevScha]

In a Hard Fork, previously invalid blocks are made valid. A Soft Fork is the opposite- previously valid blocks are made invalid by contraction of the rules.

A change in consensus rules are needed.

A few of the risks are a split in the chain, a split in the community and a weakening of the security within the blockchain.

[Long]

@ivan

• What is the difference between a softfork and a hardfork?
• What are some of the reasons why you would do a hardfork?
• What are some of the risks with performing a hardfork?

1. Hard forks make previous invalid blocks valid with an expansion in rules, whereas soft forks do the opposite which would make previous valid blocks invalid with a contraction/reduction of rule sets.
2. Modify functionality to the blockchain with consensus among community.
3. Lowered security because the split chain also splits hash power.

[MarkusJohansson]

1. What is the difference between a softfork and a hardfork?
   A Softfork comes after an contraction of the rules of set. Size of valid blocks shrinks

A hard fork comes after an expansion of the rules of set. The size of a valid block expands

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

Its more clear for the network and in a way more “democratic”

3. What are some of the risks with performing a hardfork?
   The risks are that you split your networks´s chain into 2 different chains and therefore split the community. With that also comes a decrease in hash power–>reduced security.

[acey]

1. What is the difference between a softfork and a hardfork?

Bitcoin source code updates alter the rules for block validation. A hardfork loosens the rules (making previously invalid blocks valid) and a softfork tightens the rule (making previously valid blocks invalid).

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

A hardfork update splits the network into two networks: the updated nodes and the legacy nodes. A loosening of the block validation rules means legacy nodes may not accept new blocks but updated nodes will still accept legacy blocks. This type of update is democratic - nodes aren’t forced to update if they don’t agree with the changes and may still mine in their old network if they choose.
A hardfork is also clear to understand and causes less confusion than its alternative (a softfork) as it is less tied up with backwards compatibility.

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

A hardfork has some risks accociated with it such as splitting the network in half - this will divide the hashrate between the updated and legacy networks and thereby reduce network security. It also divides the community as some of the miners will remain on the legacy chain.

[knottymoose]

1. What is the difference between a softfork and a hardfork?
   A hardfork is an expansion of the current ruleset, whist a softfork is a contraction of the current ruleset. Hard forks require 100% of the nodes to update to prevent a fork but soft forks only require 50% of nodes to update.

2. What are some of the reasons why you would do a hardfork?
   If people in the community can’t decide on which direction to go with an update, it allows miners to basically vote by putting their hash power on the preferred direction. So if the majority of miners apply the update then that chain will have more hash power. It also allows the people who do not agree to continue a blockchain under their own ruleset, however it will not be the same blockchain as before (for example BTC and BCH).

3. What are some of the risks with performing a hardfork?
   It can be incredibly devisive in the community. The BTC/BCH hard fork is still a contensious issue and the people who support BCH maintain is the true bitcoin, even though it was not backed by the hashpower. With the hashpower split, each blockchain will now be considerably less secure.

[Aki]

1. A softfork is a update that makes previoulsy valid blocks invalid. hardfork makes previously invalid blocks valid
2. It’s clear and democratic, everyone should agree before doing a hardfork update. 3. If not, it will split the chain and reduce hash power which makes the network less secure

[Ironjade]

@ivan

What is the difference between a softfork and a hardfork?

HF 1.Rules are expanded.
2.Invalid blocks are now valid.
3.Spliting of chain or 100%consensus needed.
4. Nodes can decide on witch chain they wanna stay.
SF 1.Rules are contracting.
2.Valid blocks are now invalid.
3.50% node majority needed for fork.
4. No chain split.

@ivan

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

Adding or expanding rules to upgrade the existing blockchain .

@ivan

What are some of the risks with performing a hardfork?

Chainsplit ,security ,losing hash power,less nodes and less miners.

[letscrypto]

1. A hard fork makes the validity rules less strict, while a soft fork makes them stricter.

2. If you need larger block sizes for example.

3. You run the risk of splitting the network.

[Albert777]

1 soft fork: update that makes previously valid blocks invalid.Hard fork: update that makesinvalid blocks valid.
2 reasons for a hard fork: a democratic approach that allows (for example) to create 2 independent groups inside a blockchain.
3 risks related to a hard fork:
mainly the 2 aforementioned groups now have less hashing power and this could lead to less network security.

[Eugene]

1. A softfork is an update that makes previously valid blocks invalid. And on the contrary, a hardfork is an update that makes previously invalid blocks valid. A softfork results in contraction of rule set, while a hardfork results in expansion of rule set.

2. For example to increase block size limit.

3. A chain will split as well as the community.

[Mauro]

@Von

A softfork however is an update that makes previously valid blocks invalid. It means that the rules are more strict. Therefore even if all the miners don’t update, all of them will validate the new blocks because they fit in everyone’s rules. A chain split can still happen if less than 50% of the hash power does not update.

A soft fork cannot cause a chain split.

[Mauro]

@cincinnato

What is the difference between a softfork and a hardfork?
A soft fork makes invalid the previous blocks by the new rules; a hard fork doesn’t

Soft fork contract rules, while hard forks expand them. I am a bit confused by your answer.

[Mauro]

A lot of great examples. Good homework. Keep it up.

[satsdad]

1.soft fork will run whit the old rules…hardfork if not 100% of network opdate will result in two different blockcains. 2.if you want fx another usecase . 3.That it will split in 2 cains.

[AR.18]

1- Soft fork - Update to consensus rule that makes previous valid blocks invalid
Hard fork - Update to consensus rule that makes previous invalid blocks valid

2- You would have a hard-fork to have everyone on the same page with a clear update. Either everyone has to get on with the new update or you can’t mine with the new update and continue with the old rules and thus it causes a hard fork.

3- Causes a split in the chain whilst also splits the communities