Random Mosaic – Detecting unauthorized physical access with colored rice (2021) (opens in new tab)

Old discussion https://news.ycombinator.com/item?id=31897530 (642 points | June 2022 | 165 comments)

Chaos Computer Club talk on this (using glitter nail polish) from way back in 2014...

https://www.youtube.com/watch?v=zpFKeVuP0_w

The talk covers A LOT more and focusing on "evil maid" attacks.

It's a cool idea but it kind of bothers me that with all this effort, you still only get a boolean worth of information (it was either accessed or not). No clue about who, when, where or why.

I would have never come across this except on HN & it's awesome!

there is I believ a similar thing useing paint spatters as idicators of authentisity of electronics and also as proof of tampering, as the patterns are unique and can be produced, recorded ,quickly and cheeply.

"The rice is a little more fine-grained"

nice writeup!

> If of one or more elements within the mosaic are modified, unauthorized access or compromise can be assumed.

... But how is the recipient certain of what the mosaic should be? You can't put the reference photo in the same package, because it's taken after sealing. And if you send it separately, that package is also subject to tampering.

The article anonymized a face using the compromised swirl method