Abstract: Collecting nodes receive data from multiple data sources via a communication structure. The data is processed to generate at least one meta data block reflecting information about objects of interest represented by the data content. The at least one meta data block is encrypted. The data is divided into data chunks of a respective predefined size, and encrypted. The encrypted data chunks and meta blocks are sent over the communication structure to fusion nodes, where, after decryption, meta data blocks are fused into a new meta data block if an object-of-interest criterion is fulfilled. The new meta data blocks are encrypted and sent over the communication structure. Data storage nodes store copies of the encrypted data chunks and meta data blocks in an information structure of block chains of encrypted meta data blocks organized in one chain per object of interest.