The present invention relates to a method for sharing secure data between players (5) on a net said method comprising a cryptography step for data using an asymmetrical cryptographic method with double keys, each player (5) having at least one said double key. The method includes a step for initializing (STP1) a blockchain that includes an operation for storing, at least one initialization block (26) in the blockchain by a predetermined authority using at least one computer, said at least one initialization block (26) comprising at least one said transaction (36) that includes an identity record (84) of a major player, said authority no longer intervening at the end of the initialization step (STP1) at least outside a reinitialization step of a player.