For many years in the hidden spaces of the Net, rumors have spread that cryptographic systems as we know them are worthless. Some claim that every cryptographic system out there has already been compromised because the National Security Agency only permits those systems that it has been able to tamper with in subtle ways to be published. Cryptographers they can't compromise, so the stories go, silently disappear and are never to be heard from again. More recently, advances in quantum computing have caused brand new stories to appear on forums and in IRC channels, with the requisite flame wars hot …

A long-standing problem in cryptography has been the sharing of secrets (understatement of the century, right?) Assuming that your communication medium can't be trusted because anyone and everyone could be listening in, how do you distribute keys to everyone you want to securely contact? The most obvious method is to meet up with everyone and hand them the keying material personally. However that way fraught with problems, from your courier getting ganked for the keying material to a simple matter of common sense: if you're going to meet with the intended recipient, why not just tell them and not bother …

A team of researchers at MIT have figured out how to partially compromise quantum cryptography systems through a creative interpretation of the entanglement principle. In a system protected with quantum cryptographic principles, bits of information are encoded by assigning meaning to the polarisation of individual photons of light (up-down could mean a one, left-right could mean a zero) and thus exchange keying material. The very act of observing quantum particles changes their properties and thus destroys the data encoded in the particles, so in theory an eavesdropper Somewhere Out There listening in would corrupt the stream of data by damaging …