Y</b> internal key may hold a private key, a public key, or both (a keypair), and along with those, key parameters if the key type requires them. The presence of these components determine what operations can be made; for example, signing normally requires the presence of a private key, and verifying normally requires the presence of a public key.</p>

<p><b>EVP_PKEY</b> has also been used for MAC algorithm that were conceived as producing signatures, although not being public key algorithms; &quot;POLY1305