Key Pair definition in Computer Security terms:
A public key and its corresponding private key; a key pair is used with a public key algorithm.
Source(s): CNSSI 4009-2015 (NIST SP 800-57 Part 1 Rev. 3)
NIST SP 800-21 Second edition (NIST SP 800-57)
NIST SP 800-57 Part 2
A private key and its corresponding public key; a key pair is used with an asymmetric-key (public-key) algorithm.
Source(s): NIST SP 800-133 (Superceded by Rev. 1)
Two mathematically related keys having the properties that (1) one key can be used to encrypt a message that can only be decrypted using the other key, and (ii) even knowing one key, it is computationally infeasible to discover the other key.
Source(s): NIST SP 800-32
reference: CSRC Glossary