The present invention relates to a method for controlling the identity of a user (U), comprising the following steps implemented by an identity-controlling device (3): reading, in a public database (4), confidentiality-protected data if any previously generated by an identity-attesting device (1) from an identity element of a user (U) and at least one random datum specific to the user (U); verifying (120) heed of a condition relating to the confidentiality-protected data found in the public database (4); performing predetermined processing for the user (U) only if the condition is heeded. The public database is of blockchain type and the confidentiality-protected data generated by the identity-attesting device (1) are associated in the public database (4) with first transaction data indicating that the identity-attesting device (1) has transferred a predetermined amount of electronic currency to a recipient.