I'm needing to synchronise two mysql databases between different servers on a regular basis, by a client-initiated interface. I've been doing it by remote MYSQL connection, and adding the IP of the servers to the whitelist for MYSQL remote connections. Problem is however, that the client has a dynamic IP, so as soon as it changes they can no longer sync.
So I'm trying to find an alternative way of synchronising the two databases via some sort of secure php script.
edit: I should make this a bit clearer. I've got a server (WAMP) running on a PC (Win7) the database of which I need to synchronize (both ways) to an online server. I've been doing it via remote MySQL connect, which I'd like to avoid because of dynamic IPs, and also because the local WAMP server connects to different internet connections (being a laptop) and needs to not be restricted to one IP.
However you want to synchronize the databases (replication, a PHP script, etc.), the best way to secure it would be to either use an IPSec/VPN or SSH tunnel to encrypt all the communication between the two servers. Then you'd just open a regular mysql or http connection through the tunnel.
Using either method, you'll have access to a variety of authentication modes. So you could use a pre-shared key or username/password authentication or both.
You can use an SSH client like PuTTY to initiate an SSH tunnel on a Windows systems. Or if you google IPSec and XAuth, you should be able to find some guides on how to set up an authenticated IPSec VPN.