A cryptographic key is called ephemeral if it is generated for each execution of a key establishment process. In some cases ephemeral keys are used more than once, within a single session (e.g., in 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. Contrast with a static key.
- Recommendation for Key Management — Part 1: general, NIST Special Publication 800-57
- NIST Cryptographic Toolkitru:Эфемерный ключ