DENVER (AP) -- Denver city and county officials have begun counting ballots received in Colorado's mail-in election using a system they're confident is hack-proof.
Officials began counting the votes Thursday but won't release the results until Election Day. The optical scanners and computers used to tabulate the votes aren't connected to the internet or even to city or county computers.
Denver Elections Director Amber McReynolds says the system can't be hacked from outside the facility, and the rooms are monitored 24/7 throughout the election process.
She says other security measures are in place to ensure nobody tries to get into the system.
On Election Day, the results are transferred from the election computer system to internet-connected computers using secure USB drives that are kept locked in a safe.
Denver has 390,000 voters.