Several security issues arise, due to the design of the mobile IP and its deployment in conjunction with other network protocols. Most of the work on the security of mobile IP has focused on authentication of the control packet and the confidentiality of the content in the protocol, and there are not many proposals in the area of location privacy. In this paper, we propose a method to provide location privacy for mobile IP users. We present two protocols that use an overlay network approach, and designed particularly for mobile IP. We employ universal re-encryption and extend it to n-out-of-n universal re-encryption to achieve our goal. In contrast to other overlay network approaches, where at least n public key encryption are required, our scheme requires only 2 public key encryption operations. Therefore, it is applicable to mobile IP systems, where in most cases the mobile nodes are small devices and have computational limitation.