With apologies to whoever coined the term SQUID, here's a thought experiement.
Imagine for a moment, that I choose entangle a couple of particles, kind of QKD-style.
Now I use one of these to encode my e-mail to you. Now I can use this nearly innocently to delete your copy of my email. But Imagine, for a moment, that you are fortunate (or gullible) enough to run your email service on a Quantum Computer. I can now use my entanglement to de-cohere your processor - given it is a switched program (not really a stored program) computer, I can really spin it down. I even get notified when you try to restore it and find which e-mails are causing the problem (like when you read/delete a message with one of my QUnicode bits in, my copy gets altered too - hey, that's the physics, don't mess with that:-)
What fun!
In general, has there been much analysis of side channel attacks and denial-of-service threats to QC?
