Method to secure a java software code

A method of executing, by a Java Virtual Machine run by a second processor, a java software code configured to call at least one native method of a secure native language library,

• said secure native language library:
• defining a method, called JNI_OnLoad method, which when executed at runtime, when the native language library is loaded by the Java Virtual Machine, registers useless native methods of the native language library, and
• comprising a plurality of constructors, which, when executed at runtime, triggers a thread, called zJNI thread, which unregisters said useless native methods and registers said at least one native method of the native language library to be called by the java software code,
• said method of executing comprising:
• when the Java Virtual Machine needs to execute a call to said at least one native method of the secure native language library, calling a system's LoadLibrary method to load said library,
• triggering, by a system's library loader, the execution of a plurality of constructors of said native language library, among which said constructor triggering the zJNI thread, which attaches to the Java Virtual Machine in a private context and then waits for the JNI_OnLoad method to perform its registrations of useless methods in a default context of the Java Virtual Machine executing said call to the LoadLibrary method,
• calling, by the Java Virtual Machine, the JNI_OnLoad method of the native language library, which calls a RegisterNatives method to register said useless methods and then waits or enters a useless computation loop,
• unregistering, by the zJNI thread, said useless native methods registered by the JNI_OnLoad method,
• registering, by the zJNI thread, said at least one native method to be called by the secure software code,
• ending, by the zJNI thread, said waiting or computation loop of the JNI_OnLoad method, detaching from the Java Virtual Machine, and ending itself,
• returning, by the JNI_OnLoad method and resuming the Java Virtual Machine execution.