  We use various laws of classical physics to offer several solutions of Yao's
millionaires' problem without using any one-way functions. We also describe
several informationally secure public key encryption protocols, i.e., protocols
secure against passive computationally unbounded adversary. This introduces a
new paradigm of decoy-based cryptography, as opposed to "traditional"
complexity-based cryptography. In particular, our protocols do not employ any
one-way functions.
