Zebra 7.0.0-rc.0 Adds Testnet Support for Zcash’s NU7 Upgrade

Zcash’s Zebra node software has a release candidate supporting the network’s NU7 upgrade on Testnet, where NU7 activated at block 4,465,026 on Oct. 4 as developers prepare for a possible mainnet rollout.

Zebra 7.0.0-rc.0 arrived Oct. 2 with NU7 support on Testnet. It is a release candidate for testing, and mainnet node operators were not required to upgrade to it.

The release followed three Zebra 6.4.x versions. Version 6.4.0, released Sept. 23, added security fixes and an experimental server for light-wallet clients. Version 6.4.1, also released that day, fixed a synchronization stall. Released Sept. 25, Zebra 6.4.2 addressed a denial-of-service flaw in which a malformed transaction could crash a node.

The Zcash Foundation withdrew the 6.4.0 and 6.4.1 binaries and Docker images and advised operators against running those versions.

NU7 is designed to reduce Zcash’s target block interval from 75 seconds to 25 seconds, with the goal of allowing payments to confirm about three times faster. Daily Zcash (ZEC) issuance is designed to remain unchanged. NU7 also caps shielded activity within each block and allocates some transaction fees to a reserve for future miner payments.

Zebra 6.4.x is set to stop operating around Nov. 2. Operators will need a later release with NU7 support before then. The mainnet activation height has not been set, and Nov. 5 is a tentative mainnet activation date.