Version 0.21.0 Bitcoin Core, originally slated for December 1, 2020, is now available for download and includes several notable changes to Bitcoin's main software implementation.
Specifically, Bitcoin now supports the latest Tor address format, the Taproot code is now available for testing, and Bitcoin Core has finally gotten a manual fee setting. With the rise in Bitcoin prices, these new features don't make headlines every day, but the improvements they bring to the privacy of the Bitcoin network, tools, and complex transaction logic are building a stronger foundation as the cryptocurrency meets a new wave of investor interest.
Bitcoin Core 0.21.0 was released
It is available from https://t.co/jnWN8LRX75
Release mail: https://t.co/6dFNUj3K4d- Bitcoin Core Project (@bitcoincoreorg) January 14, 2021
Taproot one step closer
The consensus rules for the highly anticipated Taproot update, which will allow for more sophisticated smart contracts using Schnorr signatures, have changed slightly since their merger with Bitcoin Core in October. Taproot also now runs entirely on Bitcoin's seal, a sandbox network where developers can test new software and updates before pushing them to the Bitcoin mainnet.
Now that the code is ready for testing, developers can test the feature prior to activation later this year.
Change in fees
Another change, made in about 3,5 years, Bitcoin Core now allows its users to set manual fees, which are expressed in satoshi (the smallest unit of bitcoins) rather than bitcoins (BTC, + 4,47%). Previously, Bitcoin Core relied on a system for estimating transaction fees, and these fees were set by specifying the amount of bitcoins (say 0,00001 BTC) instead of satoshi (1000 sat).
Confidentiality
In addition, the new version of Bitcoin Core supports the V3 address of the Tor privacy browser. Prior to this update, Tor V3 addresses could not fit into the message data that Bitcoin nodes share to communicate with each other. Core now has a new method for passing these addresses so that nodes can peer-to-peer connections through them, which is a necessary addition as the Tor V2 address will stop working by next year.
The release also introduces a new block filtering system for "light clients" (wallets that do not store the full history of the Bitcoin transaction ledger, but request data as needed from a full node). Instead of using so-called "bloom filters" to request any blocks these wallets need to make transactions, it is now possible through a process called "client-side compact filtering".
This new method is safer for light clients because the nodes create block filters for wallets in advance, and the wallet will request block data on a case-by-case basis to get the specific transaction data they need. In the old process, wallets requested data for a specific block from their peers.
Bitcoin got a new sandbox
Bitcoin is also getting a new testnet. Signet, as it is called, is now up and running and taking its place alongside other test-only Bitcoin blockchains, regtest and testnet.
The new network is centrally managed and therefore more reliable than other Bitcoin polygons; there is currently one public environment available, although developers can create their own as well.
Other notable changes to Bitcoin Core
Bitcoin Core now also supports descriptor wallets. These wallets use scripts instead of keys to perform functions, so this, among other things, will make it easier for Bitcoin Core wallets to participate in things like multi-signature transactions; it will also pave the way for hardware wallet integration.
Among many other minor changes, Bitcoin Core now supports a SQLite database, as well as a feature that reduces the number of relay attempts a node takes when it cannot broadcast a transaction to its partners. It also comes with a new dashboard for easy viewing of network information and peer data.