We use various laws of classical physics to offer several solutions of Yao's\nmillionaires' problem without using any one-way functions. We also describe\nseveral informationally secure public key encryption protocols, i.e., protocols\nsecure against passive computationally unbounded adversary. This introduces a\nnew paradigm of decoy-based cryptography, as opposed to "traditional"\ncomplexity-based cryptography. In particular, our protocols do not employ any\none-way functions.\n