This article presents a theoretical evaluation of the Simple Mutual Authentication Protocol (SMAP). After a brief description of the protocol and a qualitative comparison with some related works, the paper aims at showing that the proposed solution has a minimal cost. In order to do so, the article first presents the characteristics of the ISO/IEC 14443 smart card which is a common smart-card solution; then, an evaluation and the time analysis to perform the mutual authentication with SMAP on ISO/IEC 14443 smart cards is provided