The invention relates to a method for protecting against manipulation of a controller for at least one motor vehicle component, the control device (1) comprising at least one microcomputer (.mu.C) and at least one memory module (2, 3), at least one of the memory modules (2, 3) constituting a reversible read-only memory (3), characterized in that the reversible read-only memory (3) stores data which have been encrypted by an encryption process, and the key used in the encryption process comprises at least one part of at least one original identifier (ID) of at least one of the modules (.mu.C, 2, 3) of the control device, which identifier is specific to the module.