ONE HONEST WITNESS
Before Zcash could launch, its first shielded protocol needed public parameters. On 22–23 October 2016, six witnesses used multi-party computation to produce the proving and verifying keys for Sprout. The network launched on 28 October, several days after the ceremony.
The setup's secret byproducts were called toxic waste: combined, they could enable counterfeit Zcash. Under the protocol's assumptions, one honest, uncompromised participant securely destroying their private contribution was enough to prevent reconstruction. Recovering the combined secret required every participant to be dishonest or compromised. This did not remove all trust or rule out other software and cryptographic flaws.
The witnesses worked in separate geographic locations, with offline compute machines and removed wireless radios. Write-once DVDs carried messages across the air gap and preserved evidence. Cryptographic security depended on physical precautions as well as mathematics.
The six participants were Zooko Wilcox, Andrew Miller, Peter Van Valkenburgh, Derek Hinch, Peter Todd and Edward Snowden. Snowden took part under the name John Dobbertin; his role became public in 2022. Todd's account records further hardware destruction on 24 October, after the computation had finished.
Here, all six gather around an imagined altar as a Zcash coin rises into light. The shared room and magical apparatus are symbolic staging. Separate stations and successive phases become one image: the public result comes together, while the private material must not survive.
Sources & the artist’s interpretation
Sources: ceremony record ; ECC design account ; Sprout launch date ; Todd's account ; Snowden confirmation . Cast: back left Wilcox, back centre Miller, back right Van Valkenburgh; front left Hinch, middle right Todd, front right Snowden. Public portraits informed stylised likenesses; several are later or undated, so these are not exact 2016 appearances. ONE HONEST WITNESS is editorial wording, not a quotation.
