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A long-term key pair for which the public key is often provided in a public-key certificate.
NIST SP 800-175B Rev. 1
A key pair, consisting of a private key (i.e., a static private key) and a public key (i.e., a static public key) that is intended for use for a relatively long period of time and is typically intended for use in multiple key establishment transactions. Contrast with an ephemeral key pair.
NIST SP 800-56A Rev. 2 [Superseded]