Zcoin Development Update 27 May 2019


  • Feature freeze. Release candidate aim for 7 June 2019.
  • Mints to honor coin control to review and merge
  • Confirm to add two more denominations 0.05 and 25.
    • Significantly brings down both the average and max number of mints needed to fulfill any amount as confirmed through knapsack tests.
    • 0.05 denomination is to make the lowest Sigma spend fee cheaper without tainting spends.
  • HD Mints completed and awaiting review. Allows wallet backups to include mints.
  • Completed Electrum wallet and Electrumx server Sigma support along with update to latest Electrum code. One remaining issue when dealing with re-orgs with Electrum wallet.
  • Conversion tool from Zerocoin mints to Sigma mints to be finalized by this week.
  • To complete chain reorganization regression tests
  • RPC commands for Sigma completed
  • For wallet to prompt for full reindex if upgraded after Sigma has upgraded.
  • For DDoS or inflation protection purposes to enforce consensus limits for Sigma spends
    • Per transaction 35 spends or 500 xzc
    • Per block 50 spends or 600 xzc
  • Features that won’t make it into first mainnet release but will be added on later
    • Batch verification of Sigma spends
    • Showing total amounts of unspent mints in each denomination


  • Exodus is Zcoin’s smart asset token layer that is based off Omni
  • Discussion on implementing Sigma features in Exodus layer allowing smart assets to also have Sigma feature set. This means that tokens can be issued on Zcoin’s blockchain with privacy features
  • To look into ideal OP_return script size limit for this feature.


  • Confirm Chainlocks to be implemented during Znode code upgrade for 51% attack protection. To be worked on after Sigma deployment.
  • To look into Znode creation wizard to simplify process


  • New ccminer release is faster than CryptoDredge with OhGodAPill. Matches T-rex but slower in 20 series Nvidia GPU.
  • To look into changing the way memory is accessed for further speed ups.


  • Research is to keep up to date on improvements in the space and understanding developments in blockchain. Does not necessarily lead to improvements to Zcoin.
  • Review Spartan
  • Review RingCT 3.0
  • Review Sonic
  • Exploring some ideas to scale Lelantus
  • Understanding FloodXMR. Current status is Monero Research Labs is in contact with authors of paper to ascertain accurate costs.
  • Quadratic voting and how it may be applicable to Zcoin governance structures
  • Dynamic Znode collaterals
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