On the Connection Between Signcryption and One-Pass Key Establishment

Key establishment between two parties that uses only one message transmission is referred to as one-pass key establishment (OPKE). OPKE provides the opportunity for very efficient constructions, even though they will typically provide a lower level of security than the corresponding multi-pass variants. In this paper, we explore the intuitive connection between signcryption and OPKE. By establishing a formal relationship between these two primitives, we show that with appropriate security notions, OPKE can be used as a signcryption KEM and vice versa. In order to establish the connection we explore the definitions of security for signcryption (KEM) and give new and generalised definitions. By making our generic constructions concrete we are able to provide new examples of signcryption KEMs and an OPKE protocol.