Routing protocols have been extended over time to use cryptographic mechanisms to ensure that data received from a neighboring router has not been modified in transit and actually originated from an authorized neighboring router. The cryptographic mechanisms defined to date and described in this document rely on a digest produced with a hash algorithm applied to the payload encapsulated in the routing protocol packet. This document outlines some of the limitations of the current mechanism, problems with manual keying of these cryptographic algorithms, and possible vectors for the exploitation of these limitations. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet