We present the Plug-and-Play IP Security (PnP-IPsec) protocol. PnP-IPsec automatically establishes IPsec security associations between gateways, avoiding the need for manual administration and coordination between gateways, and the dependency on IPsec public key certificates - the two problems which are widely believed to have limited the use of IPsec mostly to intra-organization communication. PnP-IPsec builds on Self-validated Public Data Distribution (SvPDD), a protocol that we present to establish secure connections between remote peers/networks, without depending on pre-distributed keys or certification infrastructure. Instead, SvPDD uses available anonymous communication infrastructures such as Tor, which we show to allow detection of MitM attacker interfering with communication. SvPDD may also be used in other scenarios lacking secure public key distribution, such as the initial connection to an SSH server. We provide an open-source implementation of PnP-IPsec and SvPDD, and show that the resulting system is practical and secure.