The audit, which was authorized by Voatz itself, upheld findings of a February report by MIT that the company has tried to dispute.

Researchers claimed they found flaws that allowed them to alter ballots or compromise voters' anonymity, but Voatz said their findings were based on an outdated version of the app.

Five vehicles in the South Bronx will test the technology, supplied by an urban design lab at MIT, with potential for a broader deployment if the data is useful.