We present a survey of the various families of approaches to secure aggregation in distributed networks such as sensor networks. In our survey, we focus on the important algorithmic features of each approach, and provide an overview of a family of secure aggregation protocols which use resilient distributed estimation to retrieve an approximate query result that is guaranteed to be resistant against malicious tampering; we then cover a second family, the commitment-based techniques, in which the query result is exact but the chances of detecting malicious computation tampering is probabilistic. Finally, we describe a hash-tree based approach that can both give an exact query result and is fully resistant against malicious computation tampering.