In 2016, SurprizingFacts published an article on hacking 3D printers to introduce changes that lead to the destruction of the created object in the process of its operation. In short, this is an attack on businesses that use 3D printers to create parts or parts of them in order to change the configuration of manufactured items. For example, it could be a screw of the copter, parts of the car's body, parts of the machine and much more. The study of scientists was named "dr0wned – Cyber-Physical Attack with Additive Manufacturing" . In his course, specialists got access to the files of models of the details of the propeller of the drone, changed the parameters of the model, manufactured the parts and launched the drone. As a result, the screw collapsed in flight and the copter fell from a great height.
It is clear that this was only a demonstration of the possibility of an attack, which could be much larger if it were about real production. Only now, almost a year later, experts from another team have found a way that will help to resist the theoretical cracker of 3D printers. The results of this project were presented in Vancouver, at the USENIX Security Symposium.
Among other methods of tracing possible damage to parts that are printed on a 3D printer is the analysis of device operation sounds, tracking the movement of the manipulator, plus the injection of microparticles of gold into the starting material in order to make sure that everything goes according to plan.
The document describes how researchers tested their assumptions in practice. Initially, they bought three printers – Lulzbot Taz 6, Lulzbot Mini and Orion Delta. After that, the "burglars" changed the firmware of the systems, forcing the devices to print details with defects. In some cases (yes that there is – in most) on the details it was difficult to judge its quality and compliance with the original drawing. But all these details were defective and would deteriorate very quickly in the process of operation.
Scientists have thought about the possibility of using software like firewalls and antiviruses. But it is not a panacea either, since nobody has canceled the vulnerabilities of the zero day and other surprises. Therefore, it was decided to develop a different way to protect the devices and the parts they create.
This method consists of three stages. At the first stage, the printer makes the part according to the correct drawing. The operation sounds of the device are recorded and saved as a reference. Subsequently, the sounds of other printers of the same model will be recorded, which work on creating the same detail. If there are significant differences in any case, the part and printer are carefully checked.
The second stage is similar to the first – in this case, the movement of the reference printer is monitored. If the movements of other printers of the same model differ from the standard when manufacturing the same part, then everything is carefully checked.
Finally, in the third stage of the work described in the document, in the process of manufacturing the part, gold microparticles are introduced into the starting material. They are introduced not chaotically, but at a certain time, so that the particle occupies a certain place in the detail. In the future, all details are checked for correct location of gold. If everything is within the norm – ok, the part can be used. But to be faithful, the computer analyzes the recording of the sound of the printer and its movement. All three phases are tested? The item is sent to the place of use.
It's clear that the danger of hacking 3D printers is most relevant with respect to industrial systems, not home devices. Yes, if they hack the home system, it will be unpleasant for the owner, but the problem can be solved relatively quickly. But with the breaking of industrial devices, everything is not so unambiguous. As already mentioned above, complex and expensive devices that are manufactured using printers, not to mention people, can suffer.
"Imagine that a whole factory of 3D printers is working on the production of a certain kind of objects. They have no way of knowing if there are defects in the details, defects that can not be seen with the naked eye. The result can be deplorable, and no one will understand where the problem came from, "says the authors of the project.
The method proposed by scientists can also be used to determine a possible marriage that is unprovoked by a person.