  Efficient certificateless one-pass session key establishment protocols can be
constructed from key encapsulation mechanisms (KEMs) by making use of tags and
signcryption schemes. The resulting primitives are referred to as
Certificateless Signcryption Tag Key Encapsulation Mechanisms (CLSC-TKEMs). In
this paper we propose two novel CLSC-TKEM protocols, the first, named
LSW-CLSC-TKEM, makes use of the signature scheme of Liu et al., the second,
named DKTUTS-CLSC-TKEM, is based on the direct key transport using a timestamp
(DKTUTS) protocol first described by Zheng. In order to achieve greater
efficiency both schemes are instantiated on elliptic curves without making use
of pairings and are therefore good candidates for deployment on resource
constrained devices.
