600.436
High-Assurance Systems
Fall 01/Introduction
17
Definition of Security (Classical)
¨Security is usually
divided into:
–Confidentiality: preventing disclosure to unauthorized
users
–Integrity:
Ensuring that no one can tamper with good information.
–Availability: Ensure that access to information can be promptly
obtained by authorized users.
¨Informally, people
generally use security to mean confidentiality.
¨Note the
context-dependent value judgments!