Because smart grid applications generally assume access by third parties to the same physical networks and underlying IP infrastructure of the grid, much work has been done to add Secure Authentication features to the DNP3 protocol. The DNP3 protocol is compliant with IEC 62351-5. Some vendors support encryption via bump-in-the-wire for serial communications or virtual private networks for Internet Protocol-based communications. One of the most popular bump-in-the-wire methods began originally as AGA-12 (American Gas Association) in 2003, later becoming IEEE Std. 1711-2010. This standard was subsequently withdrawn March 27, 2014.