D\'ecio Luiz Gazzoni Filho
Demonstrating data possession and uncheatable data transfer
We observe that a certain RSA-based secure hash function is homomorphic. We describe a protocol based on this hash function which prevents `cheating' in a data transfer transaction, while placing little burden on the trusted third party that oversees the protocol. We also describe a cryptographic protocol based on similar principles, through which a prover can demonstrate possession of an arbitrary set of data known to the verifier. The verifier isn't required to have this data at hand during the protocol execution, but rather only a small hash of it. The protocol is also provably as secure as integer factoring.