iDIBS is a peer-to-peer backup system which optimizes the Distributed Internet Backup System (DIBS). iDIBS offers increased reliability by enhancing the robustness of existing packet transmission mechanism. Reed-Solomon erasure codes are replaced with Luby Transform codes to improve computation speed and scalability of large files. Lists of peers are automatically stored onto nodes to reduce recovery time. To realize these optimizations, an acceptable amount of data overhead and an increase in network utilization are imposed on the iDIBS system. Through a variety of experiments, we demonstrate that iDIBS significantly outperforms DIBS in the areas of data computational complexity, backup reliability, and overall performance.