Problem Constrained environments using OSCORE in network environments such as NB-IoT, 6TiSCH, and LoRaWAN need a ‘lightweight’ authenticated key exchange (LAKE) that enables forward security. 'Lightweight' refers to: * resource consumption, measured by number of round-trips to complete, bytes on the wire, wall-clock time to complete, or power consumption * the amount of new code required on end systems which already have an OSCORE stack but the LAKE must still provide the security properties expected of IETF protocols, e.g., providing confidentiality protection, integrity protection, and authentication with strong work factor. Goals This working group is intended to be a narrowly focused activity intended to produce at most one LAKE for OSCORE usage and close. The working group will collaborate and coordinate with other IETF WGs such as ACE, CORE, 6TISCH, LPWAN, and LWIG to understand and validate the requirements and solution. draft-selander-ace-cose-ecdhe is a candidate starting point for the LAKE produced by the WG. Any work available from TLS or other WGs that satisfies the determined requirements will also be evaluated for suitability, but does not preclude the WG from freely selecting its preferred LAKE for OSCORE. Program of Work The deliverables of this WG are: 1. Design requirements of the lightweight authenticated key exchange protocol for OSCORE (this draft will not be published as an RFC but will be used to drive WG consensus on the deliverable (2)) 2. Specify a lightweight authenticated key exchange protocol suitable for use in constrained environments using OSCORE