Tiered Incentives for Integrity Based Queuing Fariba Khan, Carl A. Gunter University of Illinois at Urbana-Champaign Outline • • • • • Problem setting Challenges and existing work Infrastructures for IBQ Queuing Analytic and experimental results 2 Internet DDoS Attack • Finding the source of an attack is difficult • It is often difficult to detect an attack packet 3 Internet DDoS Attack • Finding the source of an attack is difficult • It is often difficult to detect an attack packet • Legitimate client has to get through • Could we make it so that the magnitude of the attack packet is less important 4 Head of line blocking All Eve’s All Alice’s • • • • Fair-queuing Figure she is the good guy and skip the long line? No? Cannot tell if a packet is from an Alice or Eve May be give everybody opportunity to send one packet No one gets to send a million Eve 1 Eve 2 Alice 1 Eve 3 Alice 2 Eve 4 Alice 3 5 Fair-queue: Head of Line Blocking Eve Alice 1 Alice 2 Alice 3 Alice 4 Alice 5 Alice 6 Alice 7 6 Performance of Integrity Protection and Fairness ns2 Simulation Setup: Depth 10, 1024 clients/flows, 10Mbps links, 102 attackers, 10 Mbps/attacker, Client bandwidth 0.01 Mbps 100 100 Client Packet Success (%) 100 80 60 45 40 20 4.34 3.78 0 No attack, no defense Attack, no defense Attack, FQ, no spoofing Attack, FQ, spoofing Attack, FQ, spoofing (20%) 7 Source Address Validation • Ingress Filtering: Neither a complete nor verifiable • IP of a filtered domain can be spoofed – In the same domain – From an unfiltered domain 1-4 1,2 1 1 RFC 2827 2 2 1-8 1-8 3,4 3,4 3 3,4 4 1-8 5 1-8 6 1-8 1-8 7 1-8 8 8 Motivation • Effectiveness of fair-queuing is dependent on accurate flow classification. • Even with partial authentication legitimate flows can be spoofed by the spoofed origin flows. • As the legitimate flows are choked, an ISP cannot see the benefit of deploying filtering or an advanced protocol. Client: received level of service ∝ participation 9 Concept: Integrity Based Queuing (IBQ) High Integrity • Highly effective queuing • Each flow gets its own bucket • Less effective service Medium • Rate-limited flows Integrity • Shared buckets • Generic service • Rate limited Low Integrity • Least priority 10 Cycle of Network Assurance 11 Design • Integrity Levels • MAC • Queue 12 Integrity Levels: Spoofing Index Table • Strict filtering vs Regular filtering: – The address range is divided in smaller subdomains – Spoofing is restricted within that subdomain only • Example – In University of Illinois a host can spoof 511 neighboring addresses within its /23 prefix – Spoofing index = 9 for University of Illinois or AS3 • Spoofing index table for all autonomous systems available for routers BB05 13 MAC RFC4301, YPS03, YWA05, LLY08, GH09, YL09 14 Queue Per source high integrity queues =0 Spoofing Index ? >0 Per integrity-block queues Y MAC verified? N Low integrity queue 15 Analytic Results • α >> s >> β • Spoofing index, i • Probability that A and B are in the same domain, p = 1/232 – i • Loss rate, 16 Experimental Results • 2000 clients, 256 AS, 16-512 attackers • Client rate 64kbps, attacker 64 Mbps Effort = Integrity level = Success 17 Experimental Results – Example Traffic VoIP • 2000 clients, 256 AS, 16-512 attackers • Client rate 64kbps, attacker 64 Mbps 18 Experimental Results: Two Attack Styles FQ, lo integrity IBQ, hi integrity IBQ, mid integrity, si = 8, no of attacker increased IBQ, mid, integrity, only bandwidth increased Loss Rate 1.0 0.5 0.0 0 10 20 30 Attacker BW (Gbps) 19 Conclusion • Thesis – Using IBQ gives legitimate users an avenue to communicate with a server while the network is under attack. The service they get directly relates to the effort their ISP spent for integrity protection and validation thus incentivizing its investment. • Future Work – Experiment with real DDoS attack data – Overhead Measurement – Use of IBQ for network assurance 20 Thank You Questions? 21 22 Other Work [0] Adaptive Selective Verification: An Efficient Adaptive Countermeasure to Thwart DoS Attacks. S. Khanna, S. S. Venkatesh, O. Fatemieh, F. Khan, and C. A. Gunter. (Submission) IEEE Transactions on Network (ToN). [1] Attribute-Based Messaging: Access Control and Confidentiality. R. Bobba, O. Fatemieh, F. Khan, A. Khan, C. A. Gunter, H. Khurana, and M. Prabhakaran. (First three authors in alphabetic order) IN ACM Transactions on Information and System Security (TISSEC). [2] Adaptive Selective Verification, Sanjeev Khanna, Santosh S. Venkatesh, Omid Fatemieh, Fariba Khan, and Carl A. Gunter, IEEE Conference on Computer Communications (INFOCOM '08), Phoenix, AZ, April 2008. [3] Using Attribute-Based Access Control to Enable Attribute-Based Messaging, Rakesh Bobba, Omid Fatemieh, Fariba Khan, Carl A. Gunter, and Himanshu Khurana. (First three authors in alphabetic order) IEEE Annual Computer Security Applications Conference (ACSAC '06) , Miami, FL, December 2006. [4] Using Attribute-Based Access Control to Enable Attribute-Based Messaging. Fariba Khan Master's Thesis, University of Illinois, October 2006. 23 Fairness •1974: The Internet was designed with an openness •1989: FQ->active research for congestion control >RED •1999: FQ-> again for congestion control -> 40Gbps •2005: FQ-> active research for DDoS defenses 24 Related Work Analysis • • • • 1024 hosts 33 routers 32 subdomains Spoofing index: 8 (scaled down for small topology) • Links – 200 Mbps links, 10 ms delay – 5% of channel for request (10 Mbps) – Bottleneck 1Gbps – Comparative to 40-100 Gbps Internet links. • 10% hosts are attackers • Attack bandwidth 100-700 Mbps • 50B request from a client 25