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Interoperability and Common Data Formats for Voting Systems

NIST has developed common data formats (CDF) as part of its voting program so as to make voting data and ultimately voting equipment interoperable. The development work is conducted within the Voting Interoperability Public Working Group, composed of election officials, manufacturers, election analysts, and the public. The Election Assistance Commission (EAC) has indicated that it will require support for the CDF formats in the next version of the Voluntary Voting System Guidelines (VVSG).

The CDF development involves analysis of election data elements such as candidates, contests, and offices, and how they are used in voting processes. From there, specific formats (XML and JSON) are created, which can be used in voter registration and maintenance, polling place check-in, creation of cast vote records (CVR) by ballot scanners, tabulation, election results reporting, and possible other uses. To ensure that the CDF formats are consistent in their use of election data, a comprehensive glossary of election terms has been developed, used also for the next VVSG. 

Goals of the CDF work:

Overall goals include:

  • Making all voting equipment and processes “speak the same language”
  • Making voting equipment easier to use by reducing the need for translations between proprietary formats
  • Making it easier for election departments to integrate devices from different manufacturers
  • Making election devices ultimately interoperable and standalone components of a voting system

For additional overview information, see an introduction to the CDF project and an FAQ.

CDF specifications completed:

There are currently four CDF specifications completed, each located in a specific GitHub repository (see What is GitHub?).  

  1. NIST 1500-102 Cast Vote Records – for cast vote records created when scanning paper ballots, used to determine election results  - see
  2. NIST 1500-101 Election Event Logging – for election-related events logged by election devices for use in auditing - see
  3. NIST 1500-100 Election Results Reporting – for defining election and ballot information and for reporting election results - see
  4. NIST 1500-103 Voter Records Interchange – for voter registration-related records to support voter registration and for voter registration database exchanges – see

There are additionally two other CDF-related projects under development:

  1. Election Business Process Modeling - for defining and modeling election processes for the purposes of informing use case development for CDF projects and showing where interoperability between processes may be beneficial and worthwhile to pursue - see
  2. Voting Methods - a reference consisting of rigorously defined models of voting methods for counting and tabulation – see

For more information, please contact john.wack [at] (John Wack).  For specific information, contact Katy Owens Hubler for the glossary,  john [at] (John Dziurlaj) for election business process modeling, and Lauren Massa-Lochridge for voting methods.


Created July 21, 2017, Updated November 15, 2019