Huge sums of money are being spent on the development of quantum cryptography. But is there a cheaper, simpler way?
Dr. Laszlo Kish (associate professor in the Department of Electrical and Computer Engineering at Texas A&M) came up with a simple way to build a secure communications channel using inexpensive electronic parts, such as resistors and voltage monitoring circuits:
"\[My\] paper proves that classical communication measuring voltage and current can also be secure if we are doing that wisely, and it can be done much more cheaply and more easily than quantum communication. And it's superior to quantum communication because the eavesdropper has to break a few thousands of bits to get discovered in quantum communication. In my scheme, the eavesdropper can extract only a single bit before getting discovered."
Tip of the hat to Bruce Schneier, whose blog brought this paper to my attention.