With the massive amount of digital data generated everyday, data trading becomes a trend. As a result, the fairness of such transactions has drawn increasing attention in recent years. Ensuring fairness in these transactions, without relying on a Trusted Third-Party (TTP), has become a critical concern. Blockchain presents a promising solution as a fair transaction platform. When combined with Proxy Re-Encryption (PRE), smart contracts can take the role of a proxy, checking data consistency and transferring the decryption right after payment. In order to facilitate data trading, Passive Proxy Re-Encryption (PPRE) is defined and proposed. Unlike traditional PRE, where the seller (delegator) actively initiates delegation, PPRE allows delegation to occur upon the request of the buyer (delegatee). Further, by connecting the re-encryption key with the ciphertext, which means the delegation is just for the current data, the PPRE scheme is forward-secure and backward-secure. By adding the verification for the re-encryption key, PPRE supports arbitration when the interruption occurs. The proposed PPRE scheme is secure under Chosen-Ciphertext Attacks (CCA) based on the assumption of Divisible Computation Diffie-Hellman (DCDH). Theoretical analysis and experiment results validate the feasibility and effectiveness of the proposed PPRE scheme, demonstrating its potential to facilitate secure and fair data trading.