The desire to delegate computation to the cloud arises from the proliferation of small, computational restrained devices. However, to ensure the security and privacy of the stored data in the cloud, data owners always encrypt their sensitive data before outsourcing it. Nonetheless, computation outsourcing proves beneficial only when the returned result is trustworthy. Moreover, it must ensure the security and confidentiality of the computation and data during execution. Thus, the challenge lies in efficiently verifying the correctness of computation results generated over encrypted data and maintaining practical computational time for verifying results. Blockchain emerges as a trustworthy entity, enabling fairness and transparency in the scheme. We propose a secure and efficient smart contract based publicly verifiable polynomial computation with an incentive mechanism to protect confidentiality. In the proposed scheme, the smart contract is a verifier that ensures trusted verification and manages incentive transfer. We demonstrate the proposed scheme’s effectiveness through security proofs and performance analysis, significantly reducing verifier computational costs and enhancing overall efficiency.