javascript - How to keep browser client keys secure

Question

Scenes:

Under the browser, des encryption is required to generate sign and go to the background to verify whether the sign is correct, but the encryption uses a key password, such as key = 'dsadadas',

How should I call the key in the browser? It is definitely not possible to write directly to the variable, the key is a fixed value and cannot dynamically generate other

Answer 1

Only two parties know the key, so it is difficult for the middleman to get the key; and now that https has been encrypted, it is difficult for the middleman to get the body (https).