This lesson covers hybrid cryptography. In hybrid cryptography the client initiates a secure connection and the server responds by sending its public key to the client who then generates a symmetric session key. The client then encrypts ad uses the server's public key to encrypt the session key. Then, the client sends the session key (encrypted with the server's public key) to the server. The server uses its private key to decrypt the session key. Now that a symmetric key has been distributed, both parties have a secure channel across which to communicate. For the ultimate safety, obtain a digital signature by hashing a message and then have the hash encrypted by the sender's private key. Digital signatures offer authenticity, integrity and non-repudiation and gives us all the services of cryptography.