Legal protection of the software: the decompilation of the software is legitimate in case of errors

With a judgment of October 6, 2021, issued in case C13/20, the European Court of Justice clarified that the purchaser of a software has the right to decompile it in order to correct the errors that prevent its proper functioning.

The case concerned a controversy promoted against the Belgian State by T.S SA, the company author of software used by the public administration for the employees selection. Following some malfunctions of the software, the administration decompiled the software and corrected independently the errors without a prior authorization of the developer company. T.S. therefore accused the Belgian State of having decompiled the software violating thus the exclusive rights granted by Directive 91/250 to the authors of software programs.

As a matter of fact, software are copyright protected works, like literary and artistic works. In particular, in case of a software, the protection concerns the “form of expression of the program” such as its drafting in the form of a source code or object code. This means that the purchaser has the right to use the program in accordance with its destination but, without the consent of the author, they cannot carry out other operations that involve, among other things, a reproduction or a modification of the program’s code.

As recalled by the European Court, software are initially drafted in the form of a source code (i.e. in a programming language understandable to people) and, subsequently are transcribed in the form of object code (that is in a language understandable to the machine which would run the program).

This operation of transforming the source code into object code is called compilation while, on the contrary, the decompilation is the operation aimed to obtain the source code of a program starting from its object code. The result of the decompilation, in general, is never the original source code but a third version of the program, called “quasi-source code”, which can in turn be translated into another object code.

Therefore, the decompilation of the software is an operation of transformation of the code of the program that, by itself, implies a reproduction of the code and a translation of its form.

Nevertheless, if art. 5 of the Directive enables to perform the single activities of reproduction and translation of the code when such activities are necessary to use the program in accordance with its destination or to correct its errors, the activity of decompilation of the software is not equally and expressly allowed for the same purposes.

The Directive does not mention the right to decompile a software to correct its possible malfunctions, but provides it only for the cases in which the activity of decompilation of the software is essential to achieve its interoperability with other programs.

Therefore, in the case submitted to the European Court, the Belgian company affirmed that the State did not have any right to decompile the program to correct its errors given that, in their opinion, the decompilation of the software would have been legitimate only in force of an the author’s authorization or to obtain interoperability.

The Court of Justice of the European Union however did not accept this restrictive thesis and, by reinterpreting art. 5 of the Directive, stated that the legitimate purchaser of a program has the right to proceed to decompile the program to correct errors that affect its functioning.

As a matter of fact, in the majority of cases, it is necessary to have the source code (or of the quasi-source code) of the program to correct its errors.

Therefore, if the purchaser of the software were forbidden to decompile the program to correct possible malfunctions, it would prevent them from using the software in accordance to its destination, right which is expressly guaranteed to the legitimate purchaser by art. 5(1) of Directive 91/250.