The Status of SegWit at Blockstream
by Blockstream


SegWit, the Segregated Witness soft fork for Bitcoin, reached 97% signalling in early August, then went live in block 481,824 on August 24th at 01:57 UTC. This is the biggest protocol update ever for Bitcoin, in process since early December 2015. It was created as a collaboration among many participants in the Bitcoin community.

SegWit is a soft fork that is completely backward compatible, with network participants able to adopt it at their own speed. Its usage has increased since activation. As of this writing, SegWit transactions have reached 10%, while companies are activating SegWit and funds are being transferred to SegWit addresses. We expect to see many SegWit-enabled extensions and improvements in the coming months, including signature aggregation and more cross-chain atomic swaps. Blockstream’s own projects are also moving into the SegWit future:

GreenAddress, Blockstream’s non-custodial Bitcoin wallet, is directly supporting SegWit with a SegWit-enabled update to its wallet. GreenAddress had long offered this configuration in its testnet environment, and deployed it on mainnet in early September. Users can now choose to upgrade their wallets. If they do, they’ll see that fees have already halved for SegWit transactions due to the segregation of signatures.

Lightning Network, a payment channel that is supported by academia, individual contributors, and multiple startups including Blockstream, benefits from SegWit. Lightning was possible without SegWit, but the transaction malleability bug meant that chained transactions could be rendered invalid. Now, developing layer-two protocols like Lightning is easier, more flexible, and more efficient. This allows real-world usage of Lightning to advance, with a movement “Toward a Unified Lightning Network” being the next major step.

Blockstream Satellite, Blockstream’s satellite broadcast system for Bitcoin, also supports SegWit. Thanks to its basis in the Fast Internet Bitcoin Relay Engine (FIBRE), Blockstream Satellite transmissions already include the larger block sizes made possible by SegWit.

You too can join the SegWit migration. As a Bitcoin developer, join with the many companies that are already supporting SegWit: build on the new data structure, take advantage of the transaction malleability fix, or establish a new layer-two protocol. As a Bitcoin user, experience the possibilities of SegWit: convert to a SegWit wallet, receive new funds on SegWit address, and enjoy the lower fees that result.

We’ve updated Blockstream for SegWit, and we’re looking forward to what it brings to the rest of the Bitcoin ecosystem.

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