Verifiable Computing from Fully Homomorphic Encryption

In this chapter we discuss approaches to verifiable computing that use fully homomorphic encryption (FHE) as a building block. First, we define homomorphic encryption and fully homomorphic encryption. Then, we describe the verifiable computing schemes using this primitive, i.e. “Non-Interactive Verifiable Computing: Outsourcing Computation to Untrusted Workers” by Gennaro et al., “Improved Delegation of Computation Using Fully Homomorphic Encryption” by Chung et al., and “Efficient Non-Interactive Verifiable Outsourced Computation for Arbitrary Functions” by Chen et al. Note that using these solutions the client encrypts the data before it outsources it to the server. Thus, these solutions achieve input privacy. In addition, only the client can decrypt the result, which is why also output privacy is assured. However, on the downside all fully homomorphic encryption based schemes are only privately verifiable. Furthermore, all solutions are only secure against weak adversaries and providing efficient FHE schemes is still an open research challenge.