I am building a chat application (for fun and learning) and I was wondering how useful is it to regenerate RSA/AES/etc. security keys automatically during runtime? I'm envisioning something where a new RSA/AES key is generated for both clients and server(s) at arbitrary intervals (every hour or whatnot, assuming the conversation lasts that long). If it is not useful, why not? Are there similar solutions that would be better?