Method and system for authenticating the computer-aided manufacturing of a three-dimensional part

Digital watermark insertion method for the authentication of computer-aided manufacturing of a three-dimensional part by a manufacturing device using at least one predetermined manufacturing material, the three-dimensional part to be manufactured being defined by a three-dimensional model obtained by computer-aided design and represented in a predetermined file format, the manufacturing device being designed to be controlled to manufacture the part from the three-dimensional model, the method comprising obtaining a three-dimensional model of a three-dimensional part to be manufactured, comprising:

• determining a non empty subset of a global set of manufacturing parameters of the part to be manufactured, the non-empty subset of parameters comprising at least one parameter of a subset of design parameters of the manufacturing device, or at least one parameter of a set of relative parameters the manufacturing method, or at least one parameter of a subset of characteristic parameters of the at least one manufacturing material;
• generating a cryptographic key as a function of the values of the parameters of the non-empty subset of parameters;
• and
• inserting as a function of said cryptographic key of a watermark formed of a series of N bits, N being a non-zero positive integer, by applying a predetermined watermark insertion algorithm, into the three-dimensional model for obtaining a watermarked three-dimensional model of the part to be manufactured.

Digital watermark insertion device for the authentication of computer-aided manufacturing of a three-dimensional part by a manufacturing device using at least one predetermined manufacturing material, the three-dimensional part to be manufactured being defined by a three-dimensional model obtained by computer-aided design and represented in a predetermined file format, the manufacturing device being designed to be controlled to manufacture the part from the three-dimensional model, the device comprising a module designed to receive a three-dimensional model of a three-dimensional part to be manufactured, comprising:

• a module to determine a non-empty subset of a global set of manufacturing parameters of the part to be manufactured, the non-empty subset of parameters comprising at least one parameter of a subset of design parameters of the manufacturing device, or at least one parameter of a set of relative parameters the manufacturing method, or at least one parameter of a subset of characteristic parameters of the at least one manufacturing material;
• a module to generate a cryptographic key as a function of the values of the parameters of the non-empty subset of parameters;
• and
• a module to insert as a function of the cryptographic key a watermark formed of a series of N bits, N being a non-zero positive integer, by applying a predetermined watermark insertion algorithm, into the three-dimensional model to obtain a watermarked three-dimensional model of the part to be manufactured.

Authentication system of computer-aided manufacturing of a three-dimensional part by a manufacturing device, using at least one predetermined manufacturing material, the three-dimensional part to be manufactured being defined by a three-dimensional model obtained by computer-aided design and represented in a predetermined file format, the system comprising a device designed to control the manufacturing device to manufacture the part from the three-dimensional model and from a global set of manufacturing parameters, the system comprising:

• a module to generate a cryptographic key as a function of the values of the parameters of a non-empty subset of parameters of the global set of manufacturing parameters of the three-dimensional part, the non-empty subset of parameters comprising at least one parameter of a set of design parameters of the manufacturing device, or at least one parameter of a set of parameters relating to the manufacturing method. or at least one parameter a set of characteristic parameters of at least one manufacturing material;
• a module to detect a watermark in the three-dimensional model by applying a predetermined watermark detection algorithm initialized with the cryptographic key generated;
• and
• a module to compare the detected watermark with an expected watermark, and authenticate the computer-aided manufacture of the three-dimensional part in the event of a positive comparison.