Public Report – Electric Coin Company NU3 Specification and Blossom Implementation Audit

In October 2019, the Electric Coin Company engaged NCC Group to conduct a review of two Zcash improvement proposals (ZIP 213 and ZIP 221) and of the implementation of ZIP 208 within the Zcash node implementation. ZIP 213 proposes a change to consensus rules to allow coinbase transactions to target shielded addresses.  ZIP 221 describes a novel type  of hash trees meant to support efficient validation of transactions by lightweight clients. The implementation of ZIP 208 applies a change of target pacing for block issuance, so that overall network latency is halved. Two consultants performed the engagement for a total of 15 person-days.

The Public Report for this audit may be downloaded below.

[Editor’s note: Version 1.1 of this document, consisting of minor clarifications over Version 1.0, was uploaded on Thursday, February 6 2020. Version 1.1 should be considered authoritative.]