The IP level security headers, AH and ESP, were originally proposed by the Network Working Group focused on IP security mechanisms, IPSEC [5,6,2,7]. The term IPSEC will be used loosely to refer to packets, keys and routes that are associated with these headers. The IP Authentication Header (AH) is used to provide authentication. The IP Encapsulating Security Header (ESP) is used to provide confidentiality to IP datagrams. This paper will refer to two versions of the ESP header, an early version and a current version.