The U.S. Postal Service pursued a project to build and secretly test a blockchain-based mobile phone voting system before the 2020 election, experimenting with a technology that the government’s own cybersecurity agency says can’t be trusted to securely handle ballots. Matt Masterson, who was then a senior adviser to the Cybersecurity and Infrastructure Security Agency and the federal government’s chief liaison to state and local election officials, said he was never aware of the Postal Service program while in office. CISA declined to comment for this story. The Postal Service was awarded a public patent for the concept in August...