New Analysis of BAN-Yahalom Protocol by Strand Spaces and its Improvement

There´re some security flaws in the improvement of Yahalom protocol by BAN. This paper makes a detailed analysis on such flaws from a new angle induced by strand spaces. First, the algebraic model of BAN-Yahalom protocol is established with the help of strand spaces. Subsequently, attackers´ abilities are defined in an accurate math form. And then new improvement to this protocol is proposed in order to enhance the defensive ability of this protocol against potential attackers, which will make it more adaptable to practical environment. Future application of the improved protocol is also envisioned.