Bitcoin's next upgrade will support Tor V3 addresses

According to Pieter Wuille, co-founder and former engineer at Blockstream, the next version of the Bitcoin Core client will support the Tor Network’s latest V3 addresses (which will become the new standard entirely next year).

Bitcoin Core Client

v0.21 will support Tor V3 addresses and BIP155 (IP Address Payment Protocol ).

Tor V2 addresses were deprecated last month and will be disabled in October 2021

-Pieter Wuille October 11, 2020

Bitcoin Improvement Proposal (BIP) 155, which contains details of Tor support, has been merged into the current Bitcoin reference implementation. It will be pushed into Bitcoin Core version 0.21.

Merged PR from Vasil Dimov: Complete BIP155 implementation and upgrade to TORv3

- BitcoinMerges October 11, 2020

The Tor onion network is based on open source software that allows anonymous communication over the internet. In July, its developers announced that the network's V2 addresses, which have been in use for 10 years, will be "retired" on October 15, 2021. They will be replaced by the new V3 addresses that have been in development since 2015.

“As humanity’s understanding of mathematics and cryptography has evolved, the foundations of version 2 have become brittle and insecure at this time,” the statement said, adding that “a massive development effort spanning 3 years from 2015 resulted in the V3 release.”

Version 3 addresses add some significant improvements over current addresses. They use a stronger form of encryption, leak less information to anyone monitoring the network, and improve security.

Tor is a private browser and network. Image: Shutterstock

Although every relay on the Tor network supports V3 addresses today, they are not yet "the only standard." In 2020 and 2021, the network will fully migrate to the latest version, and V2 will be gradually deprecated. Eventually, developers plan to release new Tor clients on October 15, 2021, which will completely disable V2.

According to Wuille, Bitcoin Core v0.21 will be released sooner than Tor’s deadline, “probably in December of this year.” In addition to V3 addresses, Bitcoin’s new software will also support a feature called “ gossiping ,” which allows anonymous nodes to find other nodes to connect to.

Gossiping allows a node to “tell other nodes, ‘Hey, I know a cool Bitcoin Tor V3 anonymity node service running! You might want to log that down if you ever need another node to connect to it,’” Wuille explained.

As Decrypt reported, Bitcoin Core’s website passed a proposal in March to make the Tor network privacy service accessible, adding another means of censorship resistance that doesn’t rely on certificate authorities or DNS infrastructure.