The first step in the two-step key-derivation procedure during which a key-derivation key is produced. The second step in the procedure is key expansion.
Source(s):
NIST SP 800-133 Rev. 2
The first step in the key derivation procedure specified in this Recommendation, which produces a key derivation key from a shared secret.
Source(s):
NIST SP 800-56C
[Superseded]