Computational hardness assumption

In cryptography, a major goal is to create cryptographic primitives with provable security. In some cases, cryptographic protocols are found to have information theoretic security; the one-time pad is a common example. However, information theoretic security cannot always be achieved; in such cases, cryptographers fall back to computational security. Roughly speaking, this means that these systems are secure assuming that any adversaries are computationally limited, as all adversaries are in practice. Because hardness of a problem is difficult to prove, in practice certain problems are "assumed" to be difficult.