Encode-decode text by key

Question

Programming

Tell me how you can encode the text on the server side (php) so that later on the browser side (js) it can be decoded only if you know the key with which this message was encoded . Those. there will be a common stream and from it certain users will need to show certain messages by their key.

Answer 1

dren.ch/js_blowfish/ - this algorithm works by default in Mcrypt try it

Answer 2

The easiest way is XOR and checksum check

Answer 3

Mcrypt
I think that's what you need.