how ssl works https


SSL (Secure Socket Layer) is a cryptographic protocol that provides secure communication over the internet. When a user's browser initiates a request to a website that uses HTTPS, the SSL protocol performs the following steps to establish a secure connection:

  1. Client Hello: The browser sends a "Client Hello" message to the server, including its supported encryption algorithms, along with other information about the client.

  2. Server Hello: The server responds with a "Server Hello" message, including the encryption algorithm that will be used for the session, along with its own digital certificate. The digital certificate contains the server's public key, which the client will use to encrypt data that is sent to the server.

  3. Certificate Authentication: The client verifies the server's digital certificate with a trusted certificate authority. If the certificate is valid, the client generates a unique symmetric session key, which will be used for encrypting and decrypting data during the session.

  4. Session Key Exchange: The client encrypts the session key using the server's public key, and sends it back to the server. The server uses its private key to decrypt the session key.

  5. Secure Connection Established: Once the session key has been exchanged, the client and server can now securely communicate with each other, using the agreed-upon encryption algorithm and the symmetric session key.

  6. Data Transfer: All data transferred between the client and server is encrypted and decrypted using the session key, ensuring that the data is secure and cannot be intercepted by third parties.