Most zk-SNARK constructions are in the &quot;common reference string&quot; model, which requires a one-time trusted setup of a random string accessible to all parties: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Common_reference_string_model" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Common_reference_string_model</a>