1. A data set used to identify the holder of the certification and to verify, using a PKI [Public Key Infrastructure], the authenticity of the certificate. It typically includes the holder’s private key and is used for cryptographic operations such as digitally signing or encrypting data.
Source: Election Terminology Glossary - Draft, National Institute of Standards and Technology (NIST), https://pages.nist.gov/ElectionGlossary/
2. A technology by which systems and their users can employ the security applications of Public Key Infrastructure (PKI). PKI is a set of roles, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption. Voting and election systems will use PKI infrastructure to exchange and compare digital certificates for the purpose of authenticating access and securing transmission of data.
Source: Information Technology Terminology, U.S. Election Assistance Commission, https://www.eac.gov/documents/2017/09/21/information-technology-terminology-security