After Months of Testing, Bitcoin Segregated Witness Is Close to Launch

Announced in December, Segregated Witness has become one of the most talked-about technologies in the bitcoin community. If successful, the software patch would be the first step toward scaling bitcoin.

As the Bitcoin network is worth $7 billion, the development team has been moving cautiously. Previously, the Segregated Witness development team had promised to launch Segregated Witness in April, but they delayed the review of the software until May.

Eric Lombrozo, CEO of Ciphrex and spokesperson for the Bitcoin Core development team, told CoinDesk that there may still be undiscovered vulnerabilities in the current segregated verification, so the development team cannot announce a specific launch schedule.

Lombrozo noted that for “typical commonly used transaction types,” users can expect Layer 1 (the base layer of the bitcoin network) to scale 1.8 times.

However, Segregated Witness is more than just a step in Bitcoin’s scaling. Lombrozo explained that the upgrade will also make future upgrades easier to implement.

Lombrozo told CoinDesk:

“Being able to smoothly deploy this improved protocol has been a difficult challenge in the past. With Segregated Witness, we will also be able to do things that improve or replace the scripting language and build more complex smart contracts.”

While the matter of scaling is highly anticipated, there is no doubt that the new capabilities enabled by the launch of SegWit may have a greater impact on Bitcoin.

Testing Framework

However, the initial goal of SegWit was not as a way to scale the Bitcoin network. Instead, it was aimed at solving the problem of交易延展性（ transaction malleability） , which became a scapegoat in the early exchange problems of Mt. Gox.

With the goal of solving this transaction malleability issue in mind, Wuille initially implemented segregated verification on Elements Alpha (a sidechain prototype software developed by Blockstream).

After the Montreal Bitcoin Scaling Conference last September, the method of implementing the isolated verification scaling mechanism through soft forks was discussed.

Lombrozo explained that Bitcoin developer Luke-Jr first discovered Segwit without a hard fork. Instead, a backwards-compatible soft fork will allow nodes to upgrade to newer software without kicking older nodes off the entire network.

“Only miners need to upgrade,” Lombrozo explained. “Everyone else can do so at their leisure without risk of leaving the network, as the change is backwards compatible. Old wallets will continue to be able to send and receive bitcoin without any issues.”

Lombrozo explained that the Core team has deployed four independent test networks for testing Segwit, and the current one they are working on is what they call Segnet4 .

This test network is different from the Bitcoin test network, which is similar to a staging environment for the actual Bitcoin software.

It is reported that in order to ensure that the deployment of isolated verification will not cause damage to the Bitcoin network, the development team has conducted regression testing on their local computers.

"These tests are part of our test suite, and they're going to be incorporated into our continuous integration process. If any part of the build breaks something, we want to be able to detect it right away," Lombrozo said.

Once all is said and done, the team will deploy the software to the Bitcoin test network and merge it in. While the timeline for this remains unknown, Lombrozo confirmed that the team hopes to deploy it in五月份.

Encourage adoption

There are many advantages to deploying isolated verification using a soft fork. Specifically, users connected to the network will not suddenly leave the network due to laziness, technical reasons, etc.

However, because adopting Segwit is optional, benefits are maximized only when everyone upgrades to Segwit.

In addition, Lombrozo believes that the advantages of upgrading isolated verification are sufficient to motivate application developers to participate in network development.

“Not only will Segwit give them higher capacity and lower fees, but they will also be able to support other features over time with only minor upgrades,” he said.

According to the Segwit FAQ page published on the Bitcoin Core website, transactions using Segwit will also see significantly reduced transaction fees.

The website states:

“Each byte of the witness part of a segwit transaction only counts as 0.25 bytes of the transaction size. Since transaction fees are proportional to the size of the transaction, this means that the (witness part) of a transaction is discounted by 75%, but only for users using segwit.”

Another reason developers will adopt SegVerification is that the recently released CheckSequenceVerify feature is a prerequisite for SegVerification, and the deployment of the Lightning Network requires CheckSequenceVerify. If this is true, nodes on high-speed networks can expect to process thousands of transactions per second, which is a huge improvement over the current network's upper limit of 7 transactions per second.

Additionally, this is only the first phase of SegWit.

Once it is successfully launched, the development team also intends to combine signatures, which will further compress transactions. Lombrozo explained that they have not yet planned to introduce this solution because it cannot be run simultaneously with Segwit.