Any statement that have proof have zero knowledge proof

Decrypt history, Encrypt future™

Any statement that have proof have zero knowledge proof

The knowledge complexity of interactive proof-systems

https://people.csail.mit.edu/silvio/Selected%20Scientific%20Papers/Proof%20Systems/The_Knowledge_Complexity_Of_Interactive_Proof_Systems.pdf

Proofs that Yield Nothing But Their Validity All Languages in NP Have Zero-Knowledge Proof Systems

https://people.csail.mit.edu/silvio/Selected%20Scientific%20Papers/Zero%20Knowledge/Proofs_That_Yield_Nothing_But_Their_Validity_or_All_Languages_in_NP_Have_Zero-Knowledge_Proof_Systems.pdf