A secure connecter set for a liquid circuit, comprising: - a male connector and a female connector, each comprising a proximal coupler (120, 210) and a distal coupler (140, 240), - the distal coupler (140, 240) of each of the connectors (100, 200) defining a passage (141, 211) and comprising a tubular part, in which a connection element (124, 213) fixedly mounted on the proximal coupler (120, 210) extends coaxially and an elastically deformable membrane (130, 230), substantially tubular, closed at a distal end (132, 232) by a membrane thickness and mobile between a downstream blocking position, in which the membrane (130, 230) tightly covers a free end of the connection element (124, 213), and an upstream connection position, in which the connection element (124, 213) passes through the membrane (130, 230), the tubular part of the distal coupler of the male connector is adapted to be inserted, during connection, into the tubular part of the distal coupler of the female connector, wherein, in a downstream blocking position, the membrane (130, 230) of the female connector: - is encapsulated in the tubular part of the distal coupler (140, 240), - is flush with the distal end of the distal coupler (140, 240) and - tightly blocks the passage (141, 211) of said distal coupler (140, 240), the outer surface (160, 260) of the tubular part of the distal coupler (140, 240) of the female connector being smooth and having an unvarying axial cross-section over a substantially continuous part and comprising holding means (152, 252) extending transversally, said surface and said holding means (152, 252) together forming male or female locking means, the connecter set being characterized in that in a downstream blocking position, the membrane (130, 230) of the male connector: - is encapsulated in the tubular part of the distal coupler (140, 240), - is flush with the distal end of the distal coupler (140, 240) and - tightly blocks the passage (141, 211) of said distal coupler (140, 240), the outer surface (160, 260) of the tubular part of the distal coupler (140, 240) of the male connector being smooth and having an unvarying axial cross-section over a substantially continuous part and comprising holding means (152, 252) extending transversally, said surface and said holding means (152, 252) together forming male or female locking means. - a male connector and a female connector, each comprising a proximal coupler (120, 210) and a distal coupler (140, 240), - the distal coupler (140, 240) of each of the connectors (100, 200) defining a passage (141, 211) and comprising a tubular part, in which a connection element (124, 213) fixedly mounted on the proximal coupler (120, 210) extends coaxially and an elastically deformable membrane (130, 230), substantially tubular, closed at a distal end (132, 232) by a membrane thickness and mobile between a downstream blocking position, in which the membrane (130, 230) tightly covers a free end of the connection element (124, 213), and an upstream connection position, in which the connection element (124, 213) passes through the membrane (130, 230), the tubular part of the distal coupler of the male connector is adapted to be inserted, during connection, into the tubular part of the distal coupler of the female connector, - is encapsulated in the tubular part of the distal coupler (140, 240), - is flush with the distal end of the distal coupler (140, 240) and - tightly blocks the passage (141, 211) of said distal coupler (140, 240), - is encapsulated in the tubular part of the distal coupler (140, 240), - is flush with the distal end of the distal coupler (140, 240) and - tightly blocks the passage (141, 211) of said distal coupler (140, 240),