Technologies are shown for secure management of evaluation data. An evaluation value is received from a source entity. The evaluation value relates to an evaluation entity. Trusted source data secured in one or more data blocks on a first blockchain is searched for an entry corresponding to the source entity. Based on finding the entry corresponding to the source entity in the trusted source data, an evaluation score for the evaluation entity is obtained from the first blockchain or a second blockchain. The evaluation score was previously calculated based on one or more previous evaluation values for the evaluation entity and stored on the first blockchain or the second blockchain. A new evaluation score for the evaluation entity is calculated using the evaluation score and the evaluation value. The new evaluation score for the evaluation entity is securely committed to a new data block on the first blockchain or the second blockchain.