Segregated Witness (Segwit), proposed as a solution to bitcoin’s block size debate, is 99% a full proposal, a development that hasn’t occurred without some controversy.
Many expect Segwit to increase the volume of transactions without altering the block size. The change will ultimately be triggered with a soft fork, in which the majority of the nodes have to update to make the change compatible with older software versions.
The method by which the proposal has been advanced has been called political by some, including Vitalik Buterin, co-founder of Ethereum.
Unlike other proposed solutions, Segwit can be introduced to the network as a soft fork, thereby avoiding the need for bitcoin software users to upgrade their clients in near-unison. Soft fork advocates say it would reduce the risk that an upgrade would split the bitcoin blockchain.
Some observers, including bitcoin code veteran Jeff Garzik, have noted the soft fork solution is not an inclusive solution. Garzik noted in May that the soft fork is a where a few miners and developers approve changes to bitcoin economics. With the hard fork, the entire network approves the changes.
Blockstream has cited security concerns and the risk of further centralization in resisting proposals to quickly increase the permitted size of blocks, according to American Banker. But others have claimed Blockstream has a vested interest in limiting bitcoin’s volume, since doing so would drive transactions to the sidechains that Blockstream is developing.
In response, Blockstream co-founder Gregory Maxwell has noted that Blockstream uses time-locked bitcoins that cannot be accessed before a specific future date, as incentive compensation for its employees, giving them a stake in bitcoin’s long-term success.
Segwit Consensus Challenged
As Segwit reaches proposal stage, some Reddit posters raised the question about Segwit’s consensus.
Other Reddit posters noted that caps on money supply bring uncertainty about the chain’s long-term security since inflation and/or transaction fees are needed to pay for security.
The comparison to the Monero altcoin was raised. One Reddit poster noted that Monero, created without a supply cap, has experienced constant inflation.
Vitalik Buterin Weighs In
Vitalik Buterin, Ethereum creator, wrote that Segwit itself is not political; instead:
[I]t’s just a bunch of fancy technical code changes involving sticking merkle trees inside of merkle trees and reformatting transaction validation data. But Segwit was agreed upon using political means.
Buterin noted the Ethereum hard fork was also agreed upon using political means, but nobody opposed it.
Buterin further noted that Zcash is a much larger set of changes than Segwit and includes fundamental innovations. Saying innovators of this scale should be exclusively “proposing” their changes as soft forks to established cryptocurrencies is highly arrogant, he added.
Buterin noted Zcash founder and CEO Zooko is working with Ethereum on integrating “ZK-SNARK opcodes” into Ethereum.
Buterin accused bitcoin developer Peter Todd, who has advocated a “forced soft fork,” of preferring politics over markets deciding what features people can use.
Peter Todd Responds
Todd replied that Buterin is missing the point since he, Todd, is talking about a full proposal, with code built. Todd claimed that Segwit is 99% of being a full proposal, only needing activation details.
Several Twitter tweets pointed that Ethereum, which Buterin co-founded, forked to benefit a few DAO holders who lost large funds.
The Requirement As It Stands
The bitoin fork will trigger upon Segwit activation (75%) or a specific block height, whichever comes first, according to a requirement posted on GitHub. SegWit activation enables blocks with SegWit transactions on the network, requiring clients to process blocks according to Segwit rules.
The Segwit requirement on GitHub notes that Satoshi (bitcoin’s assumed founder) described a hard fork at a predetermined block height as a possible mechanism to permit larger future blocks.
Another requirement notes the fork triggering will enable blocks greater than the historical 1 million bytes, the limit that Satoshi placed as an anti-spam mechanism, not as a mechanism to limit bitcoin’s growth.
Images from Shutterstock, Github and Flickr.