How secure is JavaScript encryption

I'm developing a web project using JavaScript with AJAX requests to WebServices and I'm interested in encrypting the information.

How secure is to encrypt from the client side? Remember that I'm not using a server side langu开发者_如何学JAVAage.

There was a huge discussion on hackernews about this last week, inspired by this article on matasano.com.

Basically, secure javascript does not exist. The only way is to have everything be over HTTPS, because if you don't, you expose your user to certain flaws.

But once you have HTTPS, extra encryption via javascript is pointless: everything already is secure.

Couldn't you just have your connections be https instead of http?

Not very secure. There are little tricks here and there that you can do to make it a bit more difficult to breach the security but in the end if you give both the key and lock away to the public then you're not really secure.