The routing protocols used to disseminate routing information
throughout the Internet are not protected from intruders or faulty
router participants.  This paper reports on work in progress to protect
the OSPF routing protocol through the use of cryptography, specifically,
digital signatures.  The routing information is signed with an
asymmetric cryptographic algorithm, allowing each router recipient to
check the source and integrity of the information.  This paper discusses
the fundamental issues in security of routing protocols, reviews the
basics of OSPF operation, describes the proposed design and discusses
remaining vulnerabilities.