An example operation may include one or more of receiving, via a network, tag data that is read from a tag associated with a physical object and signed with a key assigned to the tag, determining, via a blockchain peer, that the signed tag data is validly signed based on a corresponding key pair of the tag which is accessible to the blockchain peer, determining, via the blockchain peer, whether the tag data satisfies of one or more predefined conditions of the physical object, and storing the determination via a blockchain database.