Zecnero
Zecnero vs Zcash

What Zecnero changes, and what it keeps.

Zecnero (ZMR) is Zcash at NU6 with a fixed list of changes to proof of work, difficulty, issuance, network identity and chain selection. Everything else is Zcash, taken from the specification.

At a glance

Zecnero is Zcash at network upgrade NU6 with a short, fixed list of changes. The specification (§7) lists every one; this table covers the ones a user, miner or integrator will notice.

ZecneroZcash (NU6)
Proof of workRandomX-Zecnero: RandomX v1 settings, Argon2 salt ZecneroRX + 0x01. CPU-oriented.Equihash. GPU and ASIC mined.
Header141 bytes: the Zcash layout with an empty solution fieldCarries the Equihash solution
Difficultyaserti3-2d anchored at genesis, 2-hour half-lifeAverages 17 blocks with limited adjustment; Testnet minimum-difficulty rule
Subsidy6.25 ZMR from block 1, halving every 1,680,000 blocks, 30 halvings, 20,999,993.5652 ZMR totalSlow start and the Blossom adjustment (removed in Zecnero)
AllocationFounder stream: 3% of subsidy until the first halving, 1.5% of all ZMRFounders’ Reward, funding streams and the development fund lockbox (all removed in Zecnero)
TimestampsAt most 2,700 s past the median of 11; 900 s into the future90 minutes; 2 hours
Reorganisation limit20 blocks, about 25 minutes100 blocks
TransactionsVersion 5 onlyVersions 4 and 5
Shielded poolsSapling and Orchard; Sprout removedSprout, Sapling and Orchard
Orchard circuitThe corrected NU6.2 circuit from height 1The earlier circuit from NU5 until NU6.2
P2P port8733 (Testnet 18733)8233 (Testnet 18233)
RPC port8732 (Testnet 18732)8232 (Testnet 18232)
Branch ID0x01524D5A (“ZMR” + 0x01), network magic 7A 6D 72 D1Zcash’s own; differs from every Zecnero value
AddressesN1…, N3…, ns1…, nu1…; Testnet nm…, n2…, ntestsapling1…, nutest1…t1…, t3…, zs1…, u1…
GenesisCommits to a recent Bitcoin block—

What was kept

  • All of the shielded cryptography. Sapling and Orchard keys, notes, commitments, nullifiers, note encryption, signatures and proofs are instantiated exactly as in Zcash, down to the Zcash domain-separation strings.
  • The Sapling parameters from Zcash’s multi-party ceremony, unchanged. Orchard’s Halo 2 needs none.
  • The node. zecnerod is Zebra with the changes above; everything the specification does not change follows Zcash.
  • The shape of issuance: about 21 million coins with a halving about every four years, then fees only.
  • Transparent addresses and scripts, which work as in Bitcoin and Zcash.

One consequence of keeping the cryptography: the same spending key produces the same shielded addresses on Zcash and on Zecnero. Use a separate seed, account or coin type for each network, or someone who sees both can link them. (Spec §3.1, §11.)

What was removed

  • Sprout, Zcash’s first shielded pool, with its JoinSplits and BCTV14 proofs. A new chain has no Sprout funds to support, and carrying the code adds risk.
  • Equihash and Zcash’s difficulty algorithm.
  • The Founders’ Reward, funding streams and development fund lockbox. The founder stream replaces them, at 3% instead.
  • The slow start: the full subsidy is paid from block 1.
  • Transaction versions 1 to 4, and rules that only exist to manage the transition into an upgrade Zecnero activates at height 1.
  • Zcash upgrades after NU6, NU6.1 and later, except the two NU6.2 security fixes below.

What is gated for now

Orchard. The node verifies Orchard proofs only under the corrected circuit Zcash introduced at NU6.2, from height 1, and never enables the temporary rule Zcash used to switch Orchard off while that fix was prepared. The transaction-building library that wallets use still picks the older proving key for Zecnero’s branch, so an Orchard spend built with it would be rejected by the network. Until that is fixed, the Zecnero wallet refuses Orchard and unified addresses with a clear error. The fix is on the roadmap before Mainnet.

Mainnet. Not yet launched. The wallet runs on Testnet only.

Spending mined coins on Testnet. On Mainnet, transparent coinbase outputs must be shielded before they are spent. The Testnet node relaxes that so test coins can move directly; the wallet still applies the Mainnet rule by default.

Why these changes

The goal is a launch in which ordinary computers compete on equal terms. RandomX has run Monero since 2019 and was audited before deployment; a private salt separates Zecnero from Monero’s hashrate without touching the audited design. A new chain sees sudden hashrate swings, which ASERT absorbs within hours where Zcash’s averaging window would leave blocks slow for a long time. The tighter timestamp bounds and the 20-block reorganisation limit follow from that choice. The full reasoning is in §9 of the specification.