Stephen Pair, CEO and co-founder of BitPay, said BitPay will be among the parties evaluating extension blocks as a solution to the bitcoin block size issue and encouraged others to do the same.

The bcoin development team recently released working code and specifications for extension blocks and are awaiting input from the developer community. BitPay plans to be among those parties evaluating the code, Pair noted, writing in Medium.

Pair had previously expressed his support for extension blocks as a way to avoid a contentious hard fork. Shortly after Pair voiced his support for extension blocks, bcoin informed him they have almost completed a deployment of extension blocks.

Public Testnet Available

A public testnet operating extension blocks has been released with instructions that make it possible to run a bcoin node on the extension block in minutes, Pair noted.

If the testnet holds up to scrutiny, BitPay might support its activation on the main net.

Pair has invited all bitcoiners to consider extension blocks in the interest of advancing bitcoin. He said it would be a great service to the bitcoin community.

Extension blocks create larger blockchain blocks by means of a second layer that users opt in to. The proposal, published on GitHub, has gained attention since it addresses the need to increase the bitcoin block size without requiring a hard fork.

The proposal is available for review with demo functionality and code. Pair was among the group publishing the proposal, along with Christopher Jeffrey, Purse.io CTO, Joseph Poon, a Lightning Network developer, and Fedor Indutny, a PayPal software engineer.

How It Works

Extension blocks attach to the end of a canonical block when it activates. They provide a foundation for smart contracts on the bitcoin blockchain. In one extension block deployment, funds can be transferred from the canonical block and the extension block, enhancing fungibility.

Extension blocks upgrade by means of a soft fork, a characteristic it shares with Segregated Witness.

The proposal noted that other plans for increasing the bitcoin block transaction throughput have no proposed consensus layer solutions that have been proven to be especially safe.

Extension blocks utilize features of BIP141, BIP143 and BIP144 for transaction opt-in, verification, serialization and network services, according to the draft of the specification on GitHub. The specification is an extension to the BIPs. Since extension blocks are not compatible with BIP141, additional rules are needed.

Also read: Extension blocks bid to increase bitcoin blockchain transaction

Flexibility To Increase

The extension block provides the flexibility to increase even further by means of a soft fork. It also provides the fungibility to transfer funds to and from the extension block.

Emin Gun Sirer, co-director of the Initiative for Cryptocurrencies and Smart Contracts and a Cornell associate professor, said the proposal is technically clever and politically brilliant.

But he expected opposition to the solution will come from a non-technical cause – the effort to sidestep protocol and engage the media before the development community. The extension block solution was made public early this month without first being presented to the bitcoin developer community.

When a majority of miners support Extension Blocks, users will be able to take advantage of its features.

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