Efficient cryptographic schemes provably as secure as subset sum

Abstract

Very efficient constructions, based on theintractability of the subset sum problem for certaindimensions, are shown for a pseudorandom generator andfor a universal one-way hash function. (Pseudorandomgenerators can be used for private key encryption, anduniversal one-way hash functions for signatureschemes). The increase in efficiency in theconstruction is due to the fact that many bits can begenerated\slash hashed with one application of theassumed one-way function. All the constructions can beimplemented in NC using an optimal number ofprocessors.