A common approach to overcome the limited nature of sensor networks is to aggregate data at intermediate nodes. A challenging issue in this context is to guarantee end-to-end security mainly because sensor networks are extremely vulnerable to node compromises. We propose three schemes to secure data aggregation that rely on multipath routing. The first guarantees data confidentiality through secret sharing, while the second and third provide data availability through information dispersal. Based on qualitative analysis and implementation, we show that by applying these schemes, a sensor network can achieve data confidentiality, authenticity, and protection against denial of service attacks even in the presence of multiple compromised nodes.