What is Canopy?
Canopy is the fifth major network upgrade for Zcash, coinciding with the first Zcash halving, and in accordance with the Zcash trademark agreement, it is endorsed by both Electric Coin Co. and the Zcash Foundation. Canopy will establish a new development fund for the next four years.
Miners will receive 80% of the mining reward. The remaining 20% will be divided between the new Major Grants Fund (8%), Electric Coin Co (7%), the Zcash Foundation (5%). Read more here.
The community chose “Canopy” as the name for this network upgrade to evoke themes of collaboration and a vibrant and hospitable ecosystem for many participants.
Improvements
There are five ZIPs included in Canopy. The feature selection for Canopy was determined by the Electric Coin Co and Zcash Foundation, and finalized in Release 3.1.0.
ZIP 207 and ZIP 214 are needed to establish a new development fund. ZIP 207 specifies a mechanism to support funding streams, distributed from a portion of the block subsidy for a specified range of block heights. ZIP 214 describes consensus rule changes interpreting the proposed structure of the Zcash Development Fund, which is to be enacted in Network Upgrade 4 and last for 4 years.
ZIP 211 disables the ability to add new value to the Sprout value pool balance. This takes a step toward being able to remove the Sprout protocol, thus reducing the overall complexity and attack surface of Zcash.
ZIP 212 improves the security assumptions needed to ensure that diversified addresses are not linkable. It does this by introducing a new note plaintext format for Sapling Outputs in transactions.
ZIP 215 improves the validity criteria of Ed25519 signatures used in Sprout transactions by explicitly defining criteria and changing them to be compatible with batch validation.
Consensus Branch ID
The Consensus Branch ID constant is changing for Canopy consistent with the Network Upgrade Mechanism process outlined in ZIP 200. The new constant is 0xE9FF75A6.
Version Group ID
Unlike Overwinter and Sapling, and like Blossom and Heartwood, Canopy does not define a new transaction version. Canopy transactions are therefore in the same v4 format as Sapling transactions, use the same version group ID, i.e. 0x892F2085, and use the same transaction digest algorithm.
How do I upgrade?
If you are unsure about how to upgrade your node, don’t worry! The Zcash Full Node and CLI user guide has comprehensive sections on upgrading nodes, whether they were installed from source code or the Debian package. A careful read of this guide should answer most upgrade-related questions.
Note for ASIC Miners
ASIC miners do not verify consensus rules, and Canopy does not alter the block header, so there’s no specific upgrade action needed on their part. They rely on the mining pool they’re connecting to and should verify the pool has upgraded if not identified in the list below.