A . TLS and its predecessor SSL make significant use of certificate authorities. Once your browser requests a secure page and adds the "s" onto "http," the browser sends out the public key and the certificate, checking three things: 1) that the certificate comes from a trusted party; 2) that the certificate is currently valid; and 3) that the certificate has a relationship with the site from which it's coming.
The browser then uses the public key to encrypt a randomly selected symmetric key. Public-key encryption takes a lot of computing, so most systems use a combination of public-key and symmetric key encryption. When two computers initiate a secure session, one computer creates a symmetric key and sends it to the other computer using public-key encryption. The two computers can then communicate using symmetric-key encryption. Once the session is finished, each computer discards the symmetric key used for that session. Any additional sessions require that a new symmetric key be created, and the process is repeated.
B.
1.Browser connects to a web server (website) secured with SSL (https). Browser requests that the server identify itself.
2.Server sends a copy of its SSL Certificate, including the server’s public key.
3.Browser checks the certificate root against a list of trusted CAs and that the certificate is unexpired, unrevoked, and that its common name is valid for the website that it is connecting to. If the browser trusts the certificate, it creates, encrypts, and sends back a symmetric session key using the server’s public key.
4.Server decrypts the symmetric session key using its private key and sends back an acknowledgement encrypted with the session key to start the encrypted session.
5. Server and Browser now encrypt all transmitted data with the session key.
The browser then uses the public key to encrypt a randomly selected symmetric key. Public-key encryption takes a lot of computing, so most systems use a combination of public-key and symmetric key encryption. When two computers initiate a secure session, one computer creates a symmetric key and sends it to the other computer using public-key encryption. The two computers can then communicate using symmetric-key encryption. Once the session is finished, each computer discards the symmetric key used for that session. Any additional sessions require that a new symmetric key be created, and the process is repeated.
B.
1.Browser connects to a web server (website) secured with SSL (https). Browser requests that the server identify itself.
2.Server sends a copy of its SSL Certificate, including the server’s public key.
3.Browser checks the certificate root against a list of trusted CAs and that the certificate is unexpired, unrevoked, and that its common name is valid for the website that it is connecting to. If the browser trusts the certificate, it creates, encrypts, and sends back a symmetric session key using the server’s public key.
4.Server decrypts the symmetric session key using its private key and sends back an acknowledgement encrypted with the session key to start the encrypted session.
5. Server and Browser now encrypt all transmitted data with the session key.
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