Unconditionally and computationally secure cip

Question

State the difference between unconditionally secure cipher and computationally secure cipher?

Answer 1

An unconditionally secure cipher refers to a scheme such that if the cipher text produced by the scheme does not have enough information in order to calculate uniquely the corresponding plain text, no matter how much cipher text is available.

A computationally secure scheme is such that cost of breaking the cipher exceeds the value of encrypted information and time needed to break cipher exceeds useful lifetime of information.