2. CS 325: Software Engineering April 14, 2015 Software Security Security Requirements Software Security in the Life Cycle

3. CS 325 April 14, 2015 Page 251 Security Requirements As software becomes more complex and data becomes more sensitive, software systems must meet an increasing number of security requirements. Identification Requirements The system must identify the users or systems with which it is about to interact via passwords, encryption key protocols, etc. Authentication Requirements The system must confirm the identity of the user or system that is trying to interact with it via biometrics, reverse encryption, etc. Authorization Requirements The system must determine the extent to which the user or system is authorized to access its information and functionality via access control lists, privilege hierarchies, etc.

4. CS 325 April 14, 2015 Page 252 Security Requirements Immunity Requirements The system must protect itself from malicious attacks, such as viruses, worms, and Trojan horses. Integrity Requirements The system must prevent intentional corruption via unauthorized creation, modification, or deletion of data or files. Intrusion Detection Requirements The system must be able to detect and record any unauthorized attempts to access its files or data. Nonrepudiation Requirements The system must be capable of preventing anyone who accessed its files or data from denying it later.

5. CS 325 April 14, 2015 Page 253 Security Requirements Privacy Requirements The system must protect the privacy rights of its users and of anyone affected by its data and files. Survivability Requirements The system must be able to withstand the intentional loss or destruction of its constituent files and data. Resilience Requirements The system must be able to recover adequately from any successful attack.

6. CS 325 April 14, 2015 Page 254 Software Security in the Life Cycle Security mechanisms can be put into place at several locations within the software life cycle. Requirements and Use Cases Design Test Plans Code Test Results Field Feedback Abuse Cases – Similar to use cases, they describe the system’s behavior when it’s under attack Security Reqs. – Specific security needs, like passwords and encryption Risk Analysis – Clarify req. docs. & identify possible attacks External Review – Have parties outside the design team review the design for security issues Risk-Based Security Tests – Use attack patterns & threar models to test system security Static Analysis Tools – Scan the source code for common vulnerabilities Penetration Testing – Search for architectural flaws in the fielded environment that wouldn’t appear in the development lab Security Breaks – Have the customer report post- delivery security problems so preventive measures can be put in place in future releases