A cryptographic key that is generated for each execution of a key establishment process and that meets other requirements of the key type (e.g., unique to each message or session). In some cases, ephemeral keys are used more than once within a single session (e.g., broadcast applications) where the sender generates only one ephemeral key pair per message, and the private key is combined separately with each recipient's public key. (SP 800-57 Part 1) (NISTIR)
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A cryptographic key that is generated for each execution of a key establishment process and that meets other requirements of the key type (e.g., unique to each message or session). In some cases, ephemeral keys are used more than once within a single session (e.g., broadcast applications) where the sender generates only one ephemeral key pair per message, and the private key is combined separately with each recipient's public key. (SP 800-57 Part 1) (NISTIR)
Cite this term
Election Security Glossary. (2026). Ephemeral Key. In Election Security Glossary. Retrieved August 22, 2026, from https://electionsecurityglossary.com/glossary/ephemeral-key
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