@techreport{ietf-ipsec-inline-isakmp-01, number = {draft-ietf-ipsec-inline-isakmp-01}, type = {Internet-Draft}, institution = {Internet Engineering Task Force}, publisher = {Internet Engineering Task Force}, note = {Work in Progress}, url = {https://datatracker.ietf.org/doc/draft-ietf-ipsec-inline-isakmp/01/}, author = {Bill E. Sommerfeld}, title = {{Inline Keying within the ISAKMP Framework.}}, pagetotal = 10, year = 1997, month = mar, day = 26, abstract = {The current proposal for IP-layer key management {[}ISAKMP, OAKLEY, ISAOAK{]} has fairly high overhead. Before a security association can be established, at least one pair of messages need to be exchanged between the communicating peers. For efficiency, this suggests that ISAKMP setup should be infrequent. However, general principles of key management suggest that individual keys should be used as little as practical and changed as frequently as possible. Steve Bellovin has suggested that, ideally, different security associations should be used for each different transport-level connection{[}BADESP{]}. This document discusses a way of structuring a protocol to permit this to happen with minimal overhead, both in round-trip delay at connection setup, and in bandwidth once the connection is established. The general concept of inline or in-band keying here was inspired by SKIP{[}SKIP{]}. However, SKIP's approach is burdened by the addition of an extra intermediate header of perhaps 20 to 28 bytes to every protected packet, which doubles the bandwidth overhead of protected traffic compared with ESP with fixed keying. In order to minimise the per-packet overhead, an inline keying header}, }