Answer: Internet sites use public key encryption and certificates to provide security by creating a secure channel for communication between a user's computer and the website's server. When a user connects to a secure website, the website's server sends a public key to the user's computer, which is used to encrypt data that is sent back to the server. This ensures that any data that is transmitted between the user's computer and the server is protected from interception or tampering.
To ensure the authenticity of the website and to prevent man-in-the-middle attacks, internet sites also use digital certificates. These certificates are issued by trusted third-party certificate authorities (CAs), who verify the identity of the website and issue a digital certificate that contains the website's public key. When a user connects to a secure website, their browser verifies the digital certificate with the CA to ensure that it is valid and that the website is who it claims to be.
Once the digital certificate is verified, the user's browser can use the website's public key to establish a secure communication channel with the website's server. Any data that is transmitted over this channel is encrypted using the public key, ensuring that it is protected from interception or tampering.
In summary, internet sites use public key encryption and certificates to provide security by creating a secure communication channel between the user's computer and the website's server, and by verifying the authenticity of the website using digital certificates issued by trusted third-party CAs. This helps to protect sensitive data and prevent unauthorized access or interception.
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