Read more at: http://phys.org/news/2014-01-quantum-physics-single-use-memories.html#jCp
Computer security systems may one day get a boost from quantum physics, as a result of recent research from the National Institute of Standards and Technology (NIST). Computer scientist Yi-Kai Liu has devised away to make a security device that has proved notoriously difficult to build—a "one-shot" memory unit, whose contents can be read only a single time.
The research, which Liu is presenting at this week's Innovations in Theoretical Computer Science conference, shows in theory how the laws of quantum physics could allow for the construction of such memory devices. One-shot memories would have a wide range of possible applications such as protecting the transfer of large sums of money electronically. A one-shot memory might contain two authorization codes: one that credits the recipient's bank account and one that credits the sender's bank account, in case the transfer is canceled. Crucially, the memory could only be read once, so only one of the codes can be retrieved, and hence, only one of the two actions can be performed—not both.