How SSL Work ?

SSL (Secure Sockets Layer) certificates are digital certificates that establish a secure encrypted connection between a web server and a client's web browser. They ensure the confidentiality, integrity, and authenticity of data transmitted over the internet. Here's a simplified explanation of how SSL certificates work:

1. Client initiates a secure connection: When a client (such as a web browser) attempts to establish a secure connection to a website (server), it sends a request to the server.

2. Server presents its SSL certificate: The server responds to the client's request by sending its SSL certificate, which contains the server's public key and other details. The certificate is digitally signed by a trusted Certificate Authority (CA).

3. Client verifies the certificate: The client checks the validity and authenticity of the SSL certificate. It performs several checks, including verifying the certificate's signature, ensuring it has not expired, and validating the certificate against a list of trusted CAs.

4. Client generates a session key: If the certificate is trusted, the client generates a random session key, which will be used for symmetric encryption during the secure communication session.

5. Client encrypts the session key: The client encrypts the session key using the server's public key extracted from the SSL certificate. This ensures that only the server with the corresponding private key can decrypt the session key.

6. Server receives the encrypted session key: The server receives the encrypted session key from the client.

7. Server decrypts the session key: The server decrypts the encrypted session key using its private key, which is kept securely and not shared with anyone.

8. Secure communication established: Both the client and server now have the same session key. They use this session key to encrypt and decrypt data transmitted during the secure communication session. The data is encrypted using symmetric encryption, which is faster than asymmetric encryption used for exchanging the session key.

9. Secure data transmission: With the secure connection established, all data transmitted between the client and server is encrypted using the session key, ensuring confidentiality.

SSL certificates play a crucial role in establishing trust and securing online communications. They enable secure transactions, protect sensitive information (such as login credentials or credit card details), and help verify the authenticity of websites.