Zcoin Development Update 28 February 2019


  • All cryptographic building blocks have been built
    • Sigma for double blinded commitments with batching
    • Bulletproofs for double-blinded commitmtsn with batching
    • LelantusProof and LelantusVeirfy functions which generate and verify transaction proofs with multiple input and output coins (combination of Sigma, bulletproofs and balance proofs).
  • Code clean up is happening and to be verified before implementation


  • Implementing ECDSA signature scheme similar to what we have for Zerocoin to address the “Burning Zerocoins for Fun and Profit” vulnerability.
  • Testnet is coming online soon. Slight delays due to fee handling.
  • Working on Sigma partial spend feature (where output is an arbitrary amount and the change is reminted) and should be able to push code soon.


  • New ccminer released with updated bos jansson.
  • Sgminer feedback is stable
  • CPU miner: working on some issues where cpuminer stops mining intermittently.
  • Added on Nicehash. To monitor available hashrate to evaluate 51% attack risk.
  • Hashrate has increased significantly. Pools do not suspect FPGA/ASIC as it looks to be more of a combined effect of MTP being listed as the most profitable on Whattomine and Nicehash
  • Python module for MTP being coded to evaluate whether MTP decentralized P2Pool is possible.

Core Upgrade

  • Upgrade to 0.14 is more or less complete but 0.17 is delayed
  • This is due to masternode code from Dash is designed for 0.13/0.14.
  • Using core upgrade opportunity to update masternode code then upgrade to 0.17
  • Once masternode code is integrated upgrade from 0.14 to 0.17 is simpler.

Electrum MTP

  • Detected a bug where Electrumx doesn’t react too well in chain forks. Fixing

Themis: Smart Contract Capability

  • Discussion on EVM vs WASM
  • Smart contract second layer which utilize Zcoin opcodes.
  • Discussion on whether EVM should only be validated by Znodes
  • Code is being updated to core 0.17 as well.


  • Some small bugs in relating to spending multiple Zerocoins in one tx due to the way weightage is calculated.
  • To fix completely, will need a hard fork for it to be clean. To do this with Sigma.
  • Resolving then proceeding with public beta release.
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