A function performed on a cryptographic key in order to compute a new, but related, key.
Source(s):
CNSSI 4009-2015 from NIST SP 800-57 Part 1 Rev. 3
NIST SP 800-57 Part 1 Rev. 3 [Superseded] under Key update

  A procedure in which a new cryptographic key is computed as a function of the (old) cryptographic key that it will replace.
Source(s):
NIST SP 800-133 [Superseded] under Key update

  A key-derivation process whereby the derived key replaces the key from which it was derived when the key-derivation process is later repeated.
Source(s):
NIST SP 800-152 under Key update

  A function performed on a cryptographic key in order to compute a new key that is related to the old key.
Source(s):
NIST SP 800-57 Part 1 Rev. 4 [Superseded] under Key update

  A stage in the lifecycle of keying material; alternate storage for operational keying material during its cryptoperiod.
Source(s):
NIST SP 800-57 Part 2 [Superseded] under Key update

  A function performed on a cryptographic key in order to compute a new key that is related to the old key and is used to replace that key. Note that this Recommendation disallows this method of replacing a key.
Source(s):
NIST SP 800-57 Part 1 Rev. 5 under Key update