Cryptographical formalization of computational privacy
It depends on how strict you are. In the traditional cloud computing sense, where one party "sends their data to the cloud" for all the computations to be performed, no. There aren't any other methods other than homomorphic encryption.

The most common techniques for computation on encrypted data besides homomorphic encryption are garbled circuits and secret sharing based schemes. The problem with them is that they are much more interactive than the traditional cloud computation model, where the data is encrypted and sent off.

Recent research, however, has been looking at cloud-assisted multi-party computation. In this paradigm, the cloud is a party of the MPC, but without any input. See Outsourcing Multi-Party Computation and Cloud-Assisted Multiparty Computation from Fully Homomorphic Encryption. I'm not completely aware of all the details (had forgotten about these works until working on this answer), but maybe these are headed in the direction you were thinking of.