SegWit Goes Live: Why Bitcoin's Big Upgrade Is a Blockchain Game-Changer

SegWit will finally activate on bitcoin today after years of debate. But, what exactly is the code change and what does it enable?

AccessTimeIconAug 23, 2017 at 6:24 p.m. UTC
Updated Sep 13, 2021 at 6:51 a.m. UTC

Block 481,824.

That's when Segregated Witness (SegWit) will activate on bitcoin late today or tomorrow morning, bringing the years-long debate over the contentious code upgrade to an official close. At that time, users will finally be able to take advantage of the long-promised technology.

Looking back, it's important to note how long the change – perhaps the biggest ever made to the bitcoin software – has taken. To start, the community has been embroiled in politics since SegWit was first proposed in 2015 by Bitcoin Core contributor Pieter Wuille as a possible "compromise" to the scaling debate.

Since then, there's been no shortage of drama – mining firm Bitmain was accused of blocking SegWit in order to boost its revenue; major bitcoin companies and mining pools united behind their own scaling plan; and finally, unhappy with the plan, users equipped with GIFs and branded hats responded with a kind of revolt.

And that's not even the half of it.

But with SegWit soon to be guaranteed, today marks the first day it will be usable on bitcoin. Here are the key things that SegWit enables:

  • It rearranges how data is stored in bitcoin blocks.
  • It boosts capacity while remaining compatible with past versions of the software.
  • It removes transaction malleability, a bug that's been the primary roadblock for many bitcoin projects.

Eliminating the roadblock

The final point is what might have the most lasting impact.

Indeed, many developers believe SegWit will boost the development of more forward-looking technologies necessary for bitcoin's mainstream use.

The best known is the Lightning Network, first proposed in a 2015 white paper by Joseph Poon and Tadge Dryja. The idea is payment channels that move transactions off the blockchain could boost bitcoin's capacity to millions of transactions per second.

But the project has grown in scope considerably since its 2015 ideation.

Working under the assumption that SegWit would eventually activate on bitcoin, a handful of developers have built active Lightning Network implementations, and they're now working to ensure that all of them work with one another.

And, since the Lightning Network is now possible on two major cryptocurrencies – bitcoin and litecoin – developers are also planning on using the network to create a new type of trustless trading between the two. It's also possible that these tools could potentially eradicate the need for cryptocurrency exchanges, which have been under scrutiny recently for messing up at the expense of cryptocurrency users.

And other projects that need, or at the least, work better with SegWit capability are well underway, too.

Developers preparing for SegWit activation have been working on MAST (which enables more complex bitcoin smart contracts), schnorr signatures (which would enable another transaction capacity boost) and TumbleBit (an anonymous top-layer network).

Continuing politics

And while SegWit looks to enable a bright future for bitcoin, it doesn't exactly bring an end to the debate and politics that have mired the community for years.

Some bitcoin users still believe SegWit is the wrong choice, and they're so adamant about this that they forked the bitcoin blockchain (creating a new version entirely). Called bitcoin cash, the blockchain eliminates SegWit in favor of other scaling tech.

Now, bitcoin and bitcoin cash are competing, putting two ideologies to the test – with real money on the line.

The questions being asked now are: Which cryptocurrency has the best technical roadmap? Which will attract the most users and attention? And which will remain the most decentralized? Or, do both of them have merit?

While answers to those questions are uncertain, one thing is for sure. With SegWit activating today, the community is one step closer to determining whether it's scaling capabilities are all they were touted as.

Finish line image via Shutterstock


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