How to control security from the client side?

Question

JavaScript

The Internet service provides client-side encryption. How can a client-side programmer check that, say, a password is not transmitted to the server along with the cipher?
If multiple libraries are used, can he look at the code for each of them?

Answer 1

The entire client is loaded into the browser. You cannot hide anything in client code.
In addition, the programmer can call the debugger and see how the code is being executed. Step by step, line by line. In real time. He will enter a password and will watch how this password is processed.
If the code is "assembled" by the assembler, minified and obfuscated, then the research process will take much longer. But with proper motivation, the encryption code will be fully investigated.