In July this year, we covered a story on how security researcher Cody Brocious managed to unlock the doors of some 4 million hotel rooms using an Arduino microcontroller and some programming magic, affecting Onity’s range of electronic locks. Well, it has taken just two months after this apparent flaw had gone public for other hackers to continue where Brocious left off, improving not only the success rate, but also shrunk down the unlocker into parts that are small enough to fit into your regular dry erase marker.

Watch the video above and be afraid – be very afraid. It has been refined to such a state where there are no dangling bits that come out of the marker, with a tip that looks totally normal sans any wires. All you need to do is touch the tip of the market to the door port, and you would have gained entry without mentioning a secret password.

It is rather discouraging to see Onity’s rather underwhelming response to this particular issue to date. One thing’s for sure, the name Onity will no longer be at the top of the list for hotel security worldwide. Well, since people did comment on the earlier story in July, asking for a video as proof, perhaps the video above might quell one’s doubts once and for all.

Filed in General. Read more about .