Asymmetric keys are a type of cryptographic key used in secure communications. Unlike symmetric keys, which use the same key for both encryption and decryption, asymmetric keys consist of a pair: a public key and a private key. The public key can be shared openly, while the private key is kept secret. This allows anyone to encrypt a message using the public key, but only the owner of the private key can decrypt it. This system enhances security, as the private key never needs to be transmitted or shared. Public Key Infrastructure (PKI) often employs asymmetric keys to manage digital certificates, ensuring secure online transactions and communications.