openvpn http://openvpn.net/ ・２０４８ビット鍵 Linux, Windows 2000/XP and higher, OpenBSD, FreeBSD, NetBSD, Mac OS X, and Solaris. An OpenVPN PocketPC port is under development.

http://www.amazon.co.jp/gp/product/484432229X/503-5989606-3613566?v=glance&n=465392