In brief: Microsoft said ElectionGuard isn't mean to replace paper ballots but rather, supplement and improve systems that rely on them. It also isn't designed to support Internet voting, so there's some reassurance there for those that aren't yet convinced of such technologies.

Microsoft is expanding its Defending Democracy Program with a new product called ElectionGuard. Announced at Build 2019 today, ElectionGuard is a free, open source SDK that Microsoft is developing in partnership with Portland-based Galois that is designed to boost the security and public verifiability of elections.

ElectionGuard isn't a standalone voting system but rather, an "add-on" of sorts for existing systems. According to Microsoft, it'll enable end-to-end verification of elections, allow individual voters to confirm their votes were correctly counted and open results to third-party organizations for validation.

TechCrunch provides additional insight into how the system will work:

The platform would sit underneath existing voting systems, and when a voter casts their ballot, the data would be entered in the ordinary fashion in a state's election systems, but also in ElectionGuard. The voter would then be given a tracking code that lets them see that their vote has been, say, recorded locally at the correct polling place, or perhaps that it has been sent on to state authorities for auditing.

Critically, this is done without the voting administration or Microsoft knowing how any individual actually voted through a cryptographic process called homomorphic encryption that allows mathematical processes - like counting - to be done on data that is still encrypted. Senior cryptographer Josh Benaloh has been pioneering Microsoft's use of homomorphic encryption in election systems, the company said.

Microsoft has partnered with several leading election technology providers to pilot the service and will make the ElectionGuard SDK available on GitHub this summer. They're also working to build a reference voting system to showcase ElectionGuard's capabilities.

The SDK's reference implementation will additionally provide guidance on how to set up a system on a Windows 10 platform for maximum security. It'll even include an application for integrating an Xbox Adaptive Controller to improve accessibility for those with disabilities.