Turn:
To explain this process, look at the following example:
(1) Alice needs to make a transaction on the bank's website. Her browser first generates a random number as a symmetric key .
(2) Alice's browser requests the public key from the bank's website.
(3) The bank sends the public key to Alice.
(4) Alice's browser encrypts its own symmetric key with the bank's public key .
(5) Alice's browser sends the encrypted symmetric key to the bank.
(6) The bank uses the private key to decrypt to obtain the symmetric key of Alice's browser.
(7) Alice and the bank can use the symmetric key to encrypt and decrypt the communication content.