Mobile IPv6 provides route optimization mechanism for fast communication by lessening the overhead of indirection. Although it ameliorates the communication latency but it also needs good authentication mechanism to make route optimization more effective and reliable. In this paper, we improve one of the route optimization security mechanisms called Bombing Resistant Protocol, and propose a new binding update authentication scheme. Both mechanisms perform the care of address validation of the mobile node and maintain the integrity of the binding update message during binding update process, while the latter performs better in terms of latency and computation. They also resolve reflection and amplification, intensive computation problem.