Okay this is really hard for me to explain, and I might sound stupid explaining it (I'm explaining it stupidly to get my point across.)

I'm updating my client, and I would like it so people cannot use the old client.

So how do I change the key server side.. so the old client is disabled and the new client has the new key I'm using..

I'm trying to enforce it so the new client is the only one that works...

Sorry its tough to explain and I'm not sure but I think it's using RSA Encryption?

Thanks..