This is the binary public-key value for a stored key entry, whose internal format depends on the algorithm named in keyAlgorithmIdentifier, for example an RSAPublicKey structure for RSA or an ECC publicKey format for elliptic-curve keys. An administrator would not typically decode this value by hand, but its correct association with the right algorithm identifier is what lets peers validate signatures or establish TLS trust using this key. For example, when installing a new device certificate, the issuing party must be able to verify the value in keyPublicKey matches the private key the NE holds, or the certificate chain will fail validation.