ABSTRACT

A Public-Key System secure against simulation studies, taking into account the purpose of the attacker and the model used. Among the goals there are indistinguished IND and semantic goal. The study considered as strong and concretizing for ideal security is IND-CCA, for the IBE we talk about IND-ID-CCA also: semantics-ID-CPA, semantics-ID-CCA, IND-ID-CPA .This IND-ID-CCA (as well as the others) belongs to a full domain whose identity to attack is declared in the challenge.. It is proved that the transition from selective ID to a complete domain requires a multiplication by N. The first is a HIBE based on the problem and under the Commutative Blinding approach it is known by BB1. While the second is an IBE Under the Exponent-Inversion approach named BB2, it is based on Dq-BDHIP. By combining the idea of the inverse used in BB2 and remaining in the Commutative Blinding approach, In this paper we will propose our New IBE scheme which will be efficient than BB1 and BB2.