The present description concerns a method of recording a link between a radio frequency tag and a token comprising data associated with a product. An example method comprising: sending, by near-field communication or radio identification, of data of a transaction by an electronic device to the tag; generating of a signature by the tag based on a private key of an asymmetric pair of keys further comprising a public key, the signature being configured to enable a recording on a blockchain; transmitting by the tag of the signed transaction to the electronic device by NFC or RFID; and immutable recording of the link between the tag and the token by the transmission, by the electronic device, of the signed transaction to a server implementing the blockchain.