By now it should be clear that Diebold’s AccuVote-TS electronic voting machines have lousy security. Our study last fall showed that malicious software running on the machines can invisibly alter votes, and that this software can be installed in under a minute by inserting a new memory card into the side of the machine. The last line of defense against such attacks is a cheap lock covering the memory card door. Our video shows that the lock can be picked in seconds, and, infamously, it can also be opened with a key that is widely sold for use in hotel minibars and jukeboxes.

(Some polling places cover the memory card with tamper evident seals, but these provide little real security. In practice, the seals are often ignored or accidentally broken. If broken seals are taken seriously and affected machines are taken offline for inspection, an attacker could launch a cheap denial-of-service attack by going around breaking the seals on election day.)

According to published reports, nearly all the machines deployed around the country use the exact same key. Up to this point we’ve been careful not to say precisely which key or show the particular pattern of the cuts. The shape of a key is like a password — it only provides security if you keep it secret from the bad guys. We’ve tried to keep the shape secret so as not to make an attacker’s job even marginally easier, and you would expect a security-conscious vendor to do the same.

Not Diebold. Ross Kinard of SploitCast wrote to me last month to point out that Diebold offers the key for sale on their web site. Of course, they won’t sell it to just anybody — only Diebold account holders can order it online. However, as Ross observed, Diebold’s online store shows a detailed photograph of the key.

Here is a copy of the page. The original showed the entire key, but we have blacked out the compromising part.

Could an attacker create a working key from the photograph? Ross decided to find out. Here’s what he did:

I bought three blank keys from Ace. Then a drill vise and three cabinet locks that used a different type of key from Lowes. I hoped that the spacing and depths on the cabinet locks’ keys would be similar to those on the voting machine key. With some files I had I then made three keys to look like the key in the picture.

Ross sent me his three homemade keys, and, amazingly, two of them can open the locks on the Diebold machine we used in our study!

This video shows one of Ross’s keys opening the lock on the memory card door:

Ross says he has tried repeatedly to bring this to Diebold’s attention over the past month. However, at the time of this posting, the image was still on their site.

Security experts advocate designing systems with “defense in depth,” multiple layers of barriers against attack. The Diebold electronic voting systems, unfortunately, seem to exhibit “weakness in depth.” If one mode of attack is blocked or simply too inconvenient, there always seems to be another waiting to be exposed.