The CryptoKey.type read-only property that indicates the type of the key: if it is the key for a symmetric algorithm ("secret") or for an asymmetric algorithm ("public" or "private", depending of its purpose).
result = key.type
result is an enumerated value that can be:
"secret" represents the unique key used for encrypting or decrypting a message using a symmetric algorithm.
"public" represents a publicly shareable key used in an asymmetric algorithm.
"private" represents a key used in an asymmetric algorithm that must be kept private.