Key-privacy is a notion of security that is concerned with the key anonymity in public-key encryption.Some popular schemes keep key-privacy,while others do not.Key-privacy has been shown to be orthogonal to data-privacy within one cryptosystem.This paper investigates the relationship between keyprivacy and data-privacy in public-key encryption.We show that the existence of IK-CPA secure cryptosystems implies the existence of IE-CCA secure cryptosystems in the random oracle model.The main contributions include a novel construction of a family of injective one-way trapdoor functions directly based on any IK-CPA secure public-key cryptosystem in the random oracle model.This construction adopts a novel idea in the construction compared to the existing one.The latter was based on unapproximable trapdoor predicates.The novelty of the construction allows to show that the injective trapdoor functions are secure under correlated products with respect to uniform repetitional distribution.That further allows us to conclude,in the random oracle model,that the existence of IK-CPA secure public-key cryptosystems implies the existence of CCA secure cryptosystems by a result of Rosen and Segev.