Introduction and overview • What is computer/network security? • Course philosophy and goals CS 4803 • High-level overview of topics Computer and Network Security • Course organization and information Alexandra (Sasha) Boldyreva Introduction 1 2 Broader impacts of security “Security” • Explosive growth of interest in security • Most of computer science is concerned with achieving desired behavior • Impact on/interest from most areas of CS • In some sense, security is concerned with • Theory (especially cryptography) preventing undesired behavior • Databases • Different way of thinking! • Operating systems • AI/learning theory • An enemy/opponent/hacker/adversary • Networking may be actively and maliciously trying • Computer architecture/hardware to circumvent any protective measures • Programming languages/compilers you put in place • HCI 3 4
Philosophy Student participation (I hope!) • We are not going to be able to cover • Ask questions everything • Read the textbook chapters, course notes • Main goals and papers listed on course webpage • Exposure to different aspects of • Monitor the media security; meant mainly to “pique” your • Email me relevant/interesting stories interest • The “mindset” of security: a new way of thinking… • Become familiar with basic crypto, acronyms (RSA, SSL, PGP, etc.), and “buzzwords” 5 6 High-level overview High-level overview II • Introduction… • System security • What do we mean by security? • General principles • Is security achievable…? • Security policies • Cryptography • Access control; confidentiality/integrity • Cryptography is not the (whole) solution • OS security • …but is is an important part of the solution • Along the way, we will see why cryptography can’t solve all security problems 7 8
High-level overview III High-level overview IV • Network security • Application-level security • Identity • Web-based security • Authentication and key exchange • Buffer overflows protocols • Viruses, worms, and malicious code • Some real-world protocols 9 10 Staff • Me • TA • Contact information, office hours, listed on course webpage Course Organization 11 12
Course webpage Textbooks • http://www.cc.gatech.edu/~aboldyre/ • I will primarily use two textbooks: teaching/Sp06cs4803/ • “Security in Computing” by Pfleeger • Contains course organization, updated and Pfleeger syllabus, various links, etc. • “Network Security…” by Kaufman, • Also links to papers Perlman, and Speciner • Slides posted for convenience, but no • Both will make it easier to follow the substitute for attending lecture course (but only the first one is required) • Homeworks distributed from the course • For the crypto part I will use the online webpage lecture notes of Bellare and Rogaway (links are on the course web page) • Check often for announcements 13 14 Other readings Course requirements • Will be linked from the course webpage • Homeworks and project • Please suggest other readings or relevant • About 4-5 HWs throughout the news articles! semester • Some parts (usually the programming portion) may be done with a partner • 2 exams • TAs will help with using programming • Details about project to come… 15 16
Some terminology • Confidentiality, privacy • Integrity, authenticity • Availability Security is Harder than it Seems* • Often, these are conflicting goals… *And it already seems quite hard! 17 18 “We are all Security Customers” Cost-benefit analysis • Security is always a trade-off • Important to evaluate what level of security is necessary/appropriate • The goal should never be “to make the • Cost of mounting a particular attack vs. system as secure as possible”… value of attack to an adversary • …but instead, “to make the system as secure as possible within certain • Cost of damages from an attack vs. constraints” (cost, usability, convenience) cost of defending against the attack • Likelihood of a particular attack 19 20
“More” security not always better Human factors • “No point in putting a higher post in the • E.g., passwords… ground when the enemy can go around it” • Outsider vs. insider attacks • Need to identify the weakest link • Software misconfiguration • Security of a system is only as good as • Not applying security patches the security at its weakest point… • Social engineering • Security is not a “magic bullet” • Physical security • Security is a process, not a product 21 22 Importance of precise specification Prevention not the only concern • Security policy • Detection and response • Statement of what is and is not allowed • How do you know when you are being attacked? • Security mechanism • How quickly can you stop the attack? • Method for enforcing a security policy • Can you prevent the attack from • One is meaningless without the other… recurring? • Recovery • Can be much more important than prevention • Legal issues? 23 24
“Managed security monitoring” “Trusting trust” • Is the state of network security this bad? • Whom do you trust? • Network monitoring; risk management • Does one really need to be this paranoid?? • Attacks are going to occur; impossible • Probably not to have complete protection • Security as a process, not a product… • Sometimes, yes • Shows that security is complex…and essentially impossible • Comes back to risk/benefit trade-off 25 26 Nevertheless… • In this course, we will focus on security in isolation • But important to keep in the back of your mind the previous discussion… • …and if you decide to enter the security field, learn more about it! 27
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