Monday, April 27, 2015
Eurocrypt 2015: Universal Signature Aggregators
Suppose you have a collection of signatures on different messages under different keys, and another party wants to verify that you have all of them. You could send all the signatures, and the other party could obtain the relevant public keys and then verify the signatures. However if you have a lot of signatures this is a lot of data to transfer. Aggregate signatures allow you to combine all the signatures into one of size independent of the number you have combined. Most aggregate signatures make use of algebraic properties of the underlying scheme's signatures. This means that those generating the signatures to be aggregated all have to use the appropriate scheme. Venkata Koppula's talk this morning asked if we could aggregate signatures from different schemes. He went on to answer the question in the positive, calling such a tool a universal aggregator. Syntactically, a universal signature aggregator looks like this: eprint.