Pairing based cryptography can accomplish novel security applications such as ID-based cryptosystems, which have not been constructed efficiently without the pairing. The processing speed of the pairing based cryptography is relatively slow compared with the other conventional public key cryptography. However, several efficient algorithms for computing the pairing have been proposed, namely Duursmar-Lee algorithm and its variant ηT pairing. In this paper, we present an efficient implementation of the pairing over some mobilephones, and examine the feasibility of the pairing based cryptosystems on ubiquitous devices. Indeed the processing speed of our implementation in ARM9 processors on BREW achieves under 100 milliseconds using the supersingular curve over F397. It has become fast enough for implementing security applications using the pairing on mobilephones.