Some info regarding segwit. (Stolen from
phore)
SegWit Offers Many Benefits That You May Not Be Aware Of:
1 – Transaction Malleability Fixes:
Transaction Malleability is an attack that lets someone change the unique ID of a transaction (txid) before it is confirmed on the network. SegWit fixes this by removing the signatures from the txid data, making it impossible for anyone to change the signature data. With SegWit, the txid is then calculated from data that cannot be changed.
Who benefits?
- Wallet authors tracking spent coins: easier to monitor the status of your own outgoing transactions by looking up by txid.
- Anyone spending unconfirmed transactions.
- Developers benefit because a Lightning Network is less complicated to implement and makes it possible to run lightweight Lightning clients.
- Anyone using the Blockchain because it is less complicated to design, understand and monitor.
2 –
Linear Scaling of Sighash Operations
SegWit doubles the blocksize enabling faster transactions. However, doubling the size of a transaction can double both the number of signature operations and the amount of data that has to be hashed for each signature to be verified. Without SegWit, transactions scale quadratically. SegWit allows for linear scaling. With linear scaling, an individual block requires 25 seconds to validate, and a maliciously designed transactions could take over 3 minutes.
Who benefits?
- Payments going to or from large groups. By increasing the block size, without also limiting transaction sizes, allows it to continue to support large payments.
3 –
Signing Of Input Values With Hardware Wallets
When a hardware wallet signs a transaction, it can easily verify the exact amount being spent, but can only determine the fee by having a full copy of all the input transactions being spent. This requires the network to hash each input transaction to ensure it is not being fed false data. SegWit streamlines this by explicitly hashing the input value. This means hardware wallets can simply be given the transaction hash, index and value (and told the publickey used) and can safely sign the spending transaction no matter how large or complicated.
Who benefits?
- Manufactures and users of hardware wallets.
- “Internet of Things” applications because it is easier to use in small embedded devices.
4 –
Script Versioning
Changes to scripting allows for both improved security and improved functionality. Scripting without SegWit only allows for backwards-compatible (soft-forking) changes to be implemented. With SetWit, a version number is included for scripts. By including a version number for scripts, additional opcodes that would have required a hard-fork, can instead be supported by simply increasing the script version. This avoids the necessity of a hard-fork for adding advanced features and functionality.
Who benefits?
- Developers by making advance scripting easier to code and implement.
- Everyone who owns any cryptocurrency by supporting sidechain interoperability between disparate blockchains, making crypto more flexible and functional.
- Anyone who uses the network by enabling even “smarter”, more sophisticated smart contracts.
5 –
Reducing Unspent Transaction Output (UTXO) Growth
The UTXO is a database that is maintained by each validating node in order to determine if a new transaction is valid or fraudulent. The database needs to be fast to query and modify and should be as small in size (in bytes) as possible. The more users on the network, the more UTXO entries there are to maintain, growing the size of the database.
Segwit makes signature data that does not impact the UTXO size cost 75% less than data that does increase the UTXO size. This encourages developers to design smart contracts and new features in a way that minimizes the impact on the UTXO set size.
Who benefits?
- Businesses and users who run full nodes, which in turn, helps maintain the current security of the network as more users enter the system.
- Users and developers who help minimize the growth of the UTXO set will benefit from lower fees compared to those who ignore the impact of their transactions on UTXO growth
6 –
Efficiency Gains When Not Verifying Signatures
The Blockchain network does not check signatures for transactions prior to the most recent checkpoint by default, trusting that has already been done by other nodes. Without SegWit, signature data is an integral part of the transaction and must be present to calculate the transaction hash.
Segregating the signature data allows nodes that aren’t interested in signature data to prune it from the disk, or to avoid downloading it in the first place, saving resources.
Who benefits?
- People running pruned nodes will be able to operate with less bandwidth and disk space.
7 – Block Size Increase
Since old nodes will only download the witness-stripped block, they only enforce the 1 MB block size limit rule on that data. New nodes, which understand the full block with witness data, are therefore free to replace this limit with a new one, allowing for larger block sizes. SegWit raises the block size, after new cost limits are taken into account, to up to 2MB.
Who benefits?
- Users who run upgraded wallets will be able to take advantage of the increased block size by moving signatures to the witness section of the transaction.
