EP 2 443 787 B1 relates to cryptography on a elliptical curve. Claim 1 relates to a method for performing a cryptographic calculation in an electronic component, based on a particular mathematical method. Said method comprises 3 steps.
Brief outline of the procedure
With a first decision T 80/16, the board remitted the case for further prosecution as the OD had committed a SPV.
After second decision of the OD, the patent was maintained according to a new MR.
Opponent 1/2 appealed.
AR8 was admitted in the procedure under Art 13(2) RPBA and only differs from AR2 submitted in appeal in that parameter t is “secret”.
The board decided maintenance according to AR8 which had become the MR in appeal, and remitted to the OD for the adaptation of the description.
The opponent’s point of view
The opponent argued, with regard to claim 1 of the patent as maintained, similar in this respect to the present claim 1, that its subject matter constituted merely a juxtaposition, without any functional link, of cryptography, which in its view fell within the realm of mathematics as such, and an electronic component, and that it was therefore excluded from patentability under Art 52(2).
The opponent argued inter alia that an “electronic component” could refer to a component as simple as a capacitor or resistor, meaning that the steps of the claimed process would not be carried out by that component.
The opponent further raised one objection against independent claim 6 of the maintained patent, namely lack of IS based on the application of the COMVIK approach, without referring to any specific document in the prior art.
The board’s decision
The method according to claim 1 comprises three steps.
Step 1 consists of obtaining a value for the parameter t. Claim 1 specifies that this is a “secret” parameter t. The board interpreted this feature as meaning that t represents information which, in the context of the cryptographic application mentioned in step 3, must be protected against a potential attacker.
The description provides an example of a ‘cryptographic application’ within the meaning of step 3.
Step 2 consists of determining a point P on the elliptic curve from the parameter t. The claim specifies that this step comprises sub-steps
The method is technical
For the board, the method according to claim 1 is technical in nature simply because it uses a technical means – namely an “electronic component” – to perform at least some of its steps. It thus constitutes an ‘invention’ within the meaning of Art 52(1) and is therefore not excluded from patentability under Article 52(2+3).
Cryptography = mathematics?
The board noted that the question of whether cryptography falls within the scope of ‘mathematics as such’ or constitutes a ‘technical field’ is not decisive in assessing whether the method according to claim 1 is excluded from patentability under Art 52(2+3).
For the board, a skilled person understands the expression “method of performing a cryptographic calculation in an electronic component” to imply that the cryptographic calculation is performed by that component.
The component cannot therefore be a simple passive component, such as a capacitor or resistor, but must be an electronic component capable of performing such a calculation.
COMVIK approach
The question that arises was whether, and to what extent, this mathematical method underlying claim 1 contributes to producing a technical effect that solves a technical problem in the context of the invention according to claim 1.
The board considered that the design of a mathematical method for obtaining a point P(X,Y) on an elliptic curve Y**(2)=f(X) from at least one parameter t is, as such, a non-technical problem belonging to the mathematical field of algorithmic number theory.
The mere fact that such a method may have technical applications, even if they are numerous and well known, is not sufficient in itself to confer a technical character on it, cf. G 1/19, Reasons 124.
The board held that, insofar as steps 1 and 2 contribute to a technical effect within the framework of the invention, they cannot be entirely disregarded in the assessment of IS.
In practice, it may prove difficult to identify exhaustively all the features of an invention that contribute to its technical character and those that do not.
The board observed that the reverse can also occur, namely that non-technical aspects may be ‘concealed’ in a largely technical context.
A pragmatic approach in such cases is not to make this technical/non-technical separation for the entire claimed subject matter, but to proceed directly to a comparison of the invention with the prior art and thus limit this separation to the distinctive features of the invention in relation to the CPA, as has been recommended on several occasions in case law.
However, this approach is not applicable when deciding on the merits of an objection of lack of IS based essentially on the argument that almost all of the features of the invention do not contribute to its technical character, as is the case here.
Another pragmatic approach is then possible, consisting in making the technical/non-technical separation only to a degree of granularity sufficient to be able to reject this objection, without ruling out, at this stage, that the analysis of IS in the light of the prior art may reveal that certain aspects of the invention do not contribute to its technical character.
Whichever approach is followed, what matters is that if a feature, or combination of features, is ultimately considered to justify the IS of the invention, it must in principle be possible to establish that this feature contributes to the technical character of the invention independently of any comparison with the prior art.
The board rejected the opponent’s objection of lack of IS, as it was not based on any specific document of the prior art.
Comments
The present decision is interesting in that it establishes that the COMVIK approach can reach limits.
The present decision is also interesting as it makes clear that in order to consider that a claim lacks IS it has to be compared to a piece of prior art.
This is why the opponent’s objection of lack of IS was not persuasive.
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