  The privacy-preserving data aggregation is a critical problem for many
applications where multiple parties need to collaborate with each other
privately to arrive at certain results. Blockchain, as a database shared across
the network, provides an underlying platform on which such aggregations can be
carried out with a decentralized manner. Therefore, in this paper, we have
proposed a scalable privacy-preserving data aggregation protocol for summation
on the Ethereum blockchain by integrating several cryptographic primitives
including commitment scheme, asymmetric encryption and zero-knowledge proof
along with the hypercube network topology. The protocol consists of four stages
as contract deployment, user registration, private submission and proof
verification. The analysis of the protocol is made with respect to two main
perspectives as security and scalability including computational,
communicational and storage overheads. In the paper, the zero-knowledge proof,
smart contract and web user interface models for the protocol are provided. We
have performed an experimental study in order to identify the required gas
costs per individual and per system. The general formulation is provided to
characterize the changes in gas costs for the increasing number of users. The
zero-knowledge proof generation and verification times are also measured.
