What is the difference between Data Security and Data Privacy?

I found one very good line for the difference between data security and data privacy from one of the reports I studied, which had been prepared by President's Council of Advisers on Science and Technology (PCAST), United States of America (USA). The statement was, "Security deals with tomorrow's threats against today's platforms. That is hard enough. But privacy deals with tomorrow's threats against tomorrow's platforms since those platforms comprise not just hardware and software, but also new kinds of data and new algorithms”

We can say that security is some absolute term whereas privacy is the relative term. Suppose, we have a lock and few keys for that lock. Now, we have some important data which we want to lock. Whoever is having the key, only eligible for access to the data and no one else can get access to it. It means either you have an access to whole data or to none. However, in the case of privacy, we need to have stages of locks and more no of keys because we need to share some data with someone and some other data to someone else. Hence, we want to share data selectively which is the difficult issue.

Many people think that privacy and security are same. Other thinks that privacy is part of security. I don't know how to relate these terms mathematically but I believe that privacy issues are difficult to handle than security issues.

Originally posted on 20/11/2014 at https://brijeshbmehta.wordpress.com/2014/11/20/what-is-the-difference-between-security-and-privacy/