An example operation may include one or more of receiving, by a data server node, requests for data from a plurality of user nodes connected to a blockchain, retrieving, by the data server node, the data from the blockchain, dividing, by the data server node, the data into a plurality of portions and generating copies of the plurality of the portions, changing, by the data server node, at least one bit in each of the copies, encrypting, by the data server node, the copies and recording the copies into blocks on a second blockchain, recording, by the data server node, a plurality of sequence numbers of the blocks, and storing, by the data server node, the plurality of the sequence numbers on a second blockchain to be accessed by the plurality of the user nodes.