A Note on Cryptography and NP$\cap$ CoNP-P

Diffie and Hellman [2] propose the use of the exponential function in a finite field for cryptographic purposes. The proposal is based on the conjecture that the inverse function, the logarithm, is not feasibly computable. We show that a proof of this conjecture would have important consequences for theoretical computer science, even under the assumption that P $neq$ NP.