Though I do agree that all things with a power supply/battery can be hacked, and almost 80% of time a physical Lock-And-Key protection on physical objects beats anything digital hands down. But you also have to remember that "Hacked" term is a very generic and very very broad term.
A 10th grader can run some scripties and make a windows machine show his name on command prompt. He can impress a lot of ppl by that, but from a security/system integrity its just next to nothing, it may be a flag but I wouldn't spent a min breaking my head over it.[Ps: It's just a simple hack where you change the string vals in the binary file of "cmd.exe"]
Where as a well learned security specialist can exploit the "Heart Bleed" bug in OpenSSL library to gain access to the encrypted data and read it
. It will scare the heck out of a lot people, and I will definitely spend hours trying to patch it...
Both scenarios are are included in term "Hacked". But you can clearly see the difference. Now these EVMs do not operate at any wireless frequencies, hence a wireless attack or a proximity attack is impossible. An EMF device may completely wipe/destroy the device but cannot selectively modify data. Secondly, it's a well know fact that anything can be hacked into, but no one says How long did it took, How far did they went and What kindaa H/W & S/W it took.
A Simple Googling will show that normal off-the-Shelf encryption can give even a custom build H\W pretty bad time decoding the information [ Assuming they do not know the key and the Clear test data]. We can definitely be sure of one thing that these EVMs will have nothing short of a custom concoction of encryption algorithms and these will burnt into the silicon, not in soft form. Breaking into crypto chips with visualization is a pretty daunting task with a big rig.With present day processing power and power source, breaking in those Cryptos with a handheld device without catching attention, in a brief period of time, is almost laughable.
My two cents... people, you are allowed to discuss it out with me, add to me.
[Edit: That 10th grader was, yours faithfully.....]