Decompilation

Decompilation is the operation that consists in reproducing the code of a piece of software and translating its form, from object code to a human readable form, in order to understand how it works. It constitutes in principle an act of reproduction and adaptation reserved to the author. The French Intellectual Property Code nevertheless authorises decompilation under strict conditions, in Articles L. 122-6-1 et seq., which transpose the directive on the legal protection of computer programs.

The conditions of decompilation for interoperability

First, decompilation must be indispensable to obtain the information necessary for the interoperability of an independently created program with other programs. Second, it must be performed by a person entitled to use a copy of the program, and the necessary information must not already be easily and quickly accessible. Third, it must be limited to the parts of the original program necessary for that interoperability. The information obtained may not be used for other purposes, nor communicated to third parties except where necessary, nor used to develop a substantially similar program. The provision is available on Légifrance.

Decompilation to correct errors

The Court of Justice of the European Union held, in the Top System case of 6 October 2021, that the lawful acquirer of a program may decompile it, in whole or in part, to correct errors affecting its operation, including to deactivate a function that disturbs its proper use. That faculty is distinct from the interoperability exception and cannot be excluded by contract, but it is limited to what is necessary for the correction. It informs the debates on IT maintenance contracts and on access to source code.

Key points

In practice, decompilation is a battleground between publishers and users, between competitors and between integration partners. It connects with the questions of reverse engineering, protection of trade secrets and the drafting of licence clauses. The firm advises and litigates on these questions as part of its practice in contracts and in copyright applied to software.