Privacy and security

Porthole forwards the raw bytes of the ports you share, and nothing else. It does not read or store that traffic, and it never touches your files, your other ports, or the rest of your network.

• Only the TCP or UDP ports you share.
• Only with the friends you invite, and only until you remove them.
• No files, no drives, no other services on your machine.

A VPN puts your whole machine on a shared network. Porthole does the opposite: each port is offered one at a time and only binds on a guest's machine after they approve it. You can remap it, reject it, or kick and ban a guest at any time.

Porthole runs on Steam's networking, called Steam Datagram Relay (SDR), the same system Valve's own multiplayer games use. Every connection is encrypted and tied to a real Steam account, and Steam routes it one of two ways:

• Over Valve's relay: in Valve's own words, all traffic you receive is authenticated, encrypted, and rate-limited, and your IP address is never revealed. It rides Valve's backbone, so it is often as fast as a direct link, sometimes faster.
• Direct peer-to-peer: one hop fewer, which can help latency but not always, and you and your friend exchange IP addresses to connect, so your IP is not hidden from them.
• Steam picks the faster route for each connection automatically, and thanks to Valve's backbone that is often the relay. If you would rather always stay on the relay and keep your IP private, you can force relay in Porthole's settings or in Steam's own network settings.

Lobbies can be password protected. You choose who joins and which ports each guest gets, and you can kick or ban anyone. Close Porthole and every shared port closes with it.

Porthole is being prepared for a public, open-source release, so anyone can read exactly how it works. Follow the repository on GitHub.