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BGP Security in Partial Deployment Is the Juice Worth the Squeeze?

BGP Security in Partial Deployment Is the Juice Worth the Squeeze?. Robert Lychev Sharon Goldberg Michael Schapira. Georgia Tech Boston University. Boston University. Hebrew University. Partial Landscape of BGP D efenses. What does (partially-deployed) BGPSEC offer over RPKI?

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BGP Security in Partial Deployment Is the Juice Worth the Squeeze?

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  1. BGP Security in Partial DeploymentIs the Juice Worth the Squeeze? Robert Lychev Sharon Goldberg Michael Schapira Georgia Tech Boston University Boston University Hebrew University

  2. Partial Landscape of BGP Defenses What does (partially-deployed) BGPSEC offer over RPKI? (Or, is the juice worth the squeeze?) • road to BGPSEC full-deployment is very tricky because introducing • security only partially introduces new vulnerabilities • not fully deployed BGPSEC provides only meagre benefits over RPKI • if network operators do not prioritize security in their routing policies • Security Benefits or Juice 4323,2828, FB, prefix • In standardization • Crypto done online • In deployment • Crypto done offline SP, 4323, 2828, FB, prefix 2828, FB, prefix BGP and BGPSEC coexistence S S S • RPKI (origin authentication) • BGP • BGPSEC

  3. Outline • Background: • BGP, RPKI, BGPSEC • routing policies in BGPSEC partial deployment • BGPSEC in partial deployment is tricky • Is the juice worth the squeeze? • Summary

  4. BGP 4323, 2828, D 69.63.176.0/24 Sprint Sprint, 4323, 2828, D 69.63.176.0/24 4323 2828, D 69.63.176.0/24 2828 A D 69.63.176.0/24 D 69.63.176.0/24 4

  5. The “1-hop hijack” 4323, 2828, D 69.63.176.0/24 Sprint 4323 • ? A, D 69.63.176.0/24 A 2828 • Which route to choose? • Use routing policies. • e.g. “Prefer short paths” D 69.63.176.0/24 5

  6. Prefix Hijack 4323, 2828, D 69.63.176.0/24 Sprint 4323 • ? A, D 69.63.176.0/24 A 69.63.176.0/24 A 2828 • Which route to choose? • Use routing policies. • e.g. “Prefer short paths” D 69.63.176.0/24 69.63.176.0/24 6

  7. RPKI Prevents Prefix Hijacks Sprint RPKI X RPKI invalid! 4323 A 69.63.176.0/24 Sprint checks that A is not authorized for 69.63.176.0/24 A 2828 D 69.63.176.0/24 69.63.176.0/24 Binds prefixes to ASes authorized to originate them. 7

  8. Partial Landscape of BGP Defenses assume RPKI is fully deployed, and focus on 1-hop hijack. • prevent route manipulations • prevent prefix hijacks • Security Benefits or Juice 4323,2828, FB, prefix SP, 4323, 2828, FB, prefix 2828, FB, prefix S S S • RPKI (origin authentication) • BGP • BGPSEC

  9. BGPSEC Prevents the “1-hop hijack” Sprint can verify that D never sent Sprint X BGPSEC invalid! 2828, D, prefix RPKI A, D prefix 4323 4323, 2828, D, prefix • ? A, D, prefix 4323,2828, D, prefix A 2828 SP, 4323, 2828, D, prefix SP, A, D, prefix 2828, D, prefix 2828, D, prefix D S P/S P/S P/S S P/S S P/S S S S S S 69.63.176.0/24 9

  10. Partial Landscape of BGP Defenses assume RPKI is fully deployed, and focus on 1-hop hijack. • prevent route manipulations • prevent prefix hijacks • Security Benefits or Juice 4323,2828, FB, prefix SP, 4323, 2828, FB, prefix 2828, FB, prefix What happens when BGP and BGPSEC coexist? S S S • RPKI (origin authentication) • BGP • BGPSEC

  11. What Happens in Partial BGPSEC Deployment? • ? Should Sprint choose the long secure path OR the short insecure one? Sprint Secure ASes must accept legacy insecure routes RPKI 4323 A, D 69.63.176.0/24 4323,2828, D, prefix A 2828 SP, 4323, 2828, D, prefix 2828, D, prefix Siemens D P/S P/S P/S P/S S P/S P/S S S 69.63.176.0/24 Depends on the interaction between BGPSEC and routing policies! 11

  12. BGP Decision Process • local preference (often based on business relationships with neighbors) 2. prefer short routes … 3. break ties in a consistent manner

  13. How to Prioritize Security? Cost, Performance Security Cost, Performance Security Security 1st • local preference (cost) (often based on business relationships with neighbors) Security 2nd 2. prefer short routes (performance) Security 3rd 3. break ties in a consistent manner • Survey of 100 network operators shows that 10%, 20% and 41% • would place security 1st, 2nd, and 3rd,[Gill, Schapira, Goldberg’12]

  14. Our Routing Model Security 1st • local preference (cost) (prefer customer routes over peer over provider routes) Security 2nd 2. prefer short routes (performance) Security 3rd 3. break ties in a consistent manner • To simulate routing outcomes, we use a concrete model of local preference.[Gao-Rexford’00, Huston’99, etc.] • Our ongoing work tests the robustness of this local pref model.

  15. Outline • Background: BGP, RPKI, BGPSEC, routing policies • BGPSEC in partial deployment is tricky • Protocol downgrade attacks • Collateral damages • Routing instabilities • Is the Juice worth the squeeze? • Summary

  16. Protocol Downgrade Attack, Security 3rd! • ? Security 3rd: Path length trumps path security! Sprint 4323 A, D 69.63.176.0/24 4323,2828, D, prefix A 2828 SP, 4323, 2828, D, prefix 2828, D, prefix D P/S P/S S P/S P/S S S 69.63.176.0/24 Protocol downgrade attack: Before the attack, Sprint has a legitimate secure route. During the attack, Sprint downgrades to an insecure bogus route . 16

  17. Partial Deployment is Very Tricky! A • ? Sprint Protocol downgrade attack:A secure AS with a secure route before the attack, downgrades to an insecure bogus route during the attack. 4323 P/S P/S P/S P/S P/S A, D 69.63.176.0/24 2828 Siemens D 69.63.176.0/24

  18. Collateral Damages; Security 2nd 20960 3257 52142 12389 3356 5617 174 3491 10310 P/S P/S P/S P/S P/S M 7922 40426 prefix

  19. Collateral Damages; Security 2nd Before X deploys BGPSEC W • ? Y X offers the shorter path Secure ASes: 5 Happy ASes: 8 Z X V • ? Shorter path! P/S P/S P/S P/S P/S M D prefix

  20. Collateral Damages; Security 2nd After X deploys BGPSEC W • ? Y experiences collateral damage because X is secure! Y W offers the shorter path! Z X V • ? Security 2nd: Security trumps path length! Secure ASes: 6 Happy ASes: 7 P/S P/S P/S P/S P/S P/S M D prefix

  21. Partial Deployment is Very Tricky! 20960 3257 Collateral damage (during the attack): Moresecure ASes leads to more insecure ASes choosing bogus routes • ? 52142 P/S P/S P/S P/S P/S P/S 12389 A 3356 5617 5617 174 • ? 3491 10310 prefix 7922 40426

  22. Partial Deployment is Very Tricky! Theorem: Routing converges to a unique stable state if all ASes use thesame secure routing policy model.  But, if they don’t, there can be BGP Wedgies and oscillations.

  23. Outline • Background: BGP, RPKI, BGPSEC, routing policies • BGPSEC in partial deployment is tricky • Is the Juice worth the Squeeze? • Can we efficiently select the optimal set of secure ASes? • Can we bound security benefits invariant to who is secure? • Is the BGPSEC juice worth the squeeze given RPKI? • Summary

  24. Quantifying Security: A Metric Let S be the set of ASes deploying BGPSEC, Abe the attacker and d be the destination The set of ASes choosing a legitimate route is 5617 174 20960 3257 3491 52142 12389 10310 3356 5617 7922 • ? d | Happy(S, A, d)| = 7 prefix A Happy S, , d prefix A

  25. Quantifying Security: A Metric Let S be the set of ASes deploying BGPSEC, Abe the attacker and d be the destination Our metric is the average of the set of Happy ASes 5617 174 20960 3257 3491 52142 12389 10310 ∑ 3356 5617 7922 • ? d | Happy(S, A, d)| = 7 prefix allA alld A 1 Happy S, , Metric(S) = 3 |V| d prefix A

  26. It is Hard to Decide Whom to Secure Problem: find set S of secure ASes that maximizes s. t. |S| = k, for a fixed attacker A and destination d Theorem: This problem is NP-hard for all three routing models. Happy S, , d prefix A

  27. Bound Security Benefits for any S! Problem: Compute upper and lower bounds on for any BGPSEC deployment set S Happy S, , Metric(S) = ∑ allA alld 1 3 |V| d prefix A

  28. Bounding Security Metric. Security 3rd Sprint The bogus path is shorter! 4323 A, D 69.63.176.0/24 A 2828 Siemens D 69.63.176.0/24 28

  29. Bounding Security Metric. Security 3rd Sprint Sprint is doomed The bogus path is shorter! 4323 A, D 69.63.176.0/24 A 2828 Siemens D P/S P/S P/S P/S P/S 69.63.176.0/24 Regardless of who is secure, Sprint will select the shorter bogus route! 29

  30. Bounding Security Metric. Security 3rd Sprint Sprint is doomed The bogus path is shorter! The legitimate path is shorter! 4323 A, D 69.63.176.0/24 A 2828 Siemens D P/S P/S P/S P/S P/S 69.63.176.0/24 30

  31. Bounding Security Metric. Security 3rd Sprint Sprint is doomed The bogus path is shorter! 2828 and 4323 are immune The legitimate path is shorter! 4323 A, D 69.63.176.0/24 A 2828 Siemens D 69.63.176.0/24 Regardless of who is secure, 4323 and 2828 will select legitimate routes! 31

  32. Different Idea: Bound Security Benefits! Problem: Find upper and lower bound on Happy S, , Metric(S) = ∑ allA alld • Key observation. Regardless of who is secure: • Doomed ASeswill always choose bogus routes • Immune ASeswill always choose legitimate routes • Lower bound on Metric(S) = fraction of immune ASes • Upper bound on Metric(S) = 1 – fraction of doomed ASes 1 3 |V| d prefix A

  33. Security Benefits Bounds over RPKI upper bound with BGPSEC 47% 36% 17% 53% Average Fraction of Happy ASes lower bound with RPKI results based on simulations on empirical AS-level graphs In the most realistic security 3rd model, the best we could do is make extra 17% happy with security!

  34. Securing 113 High Degree ASes & their Stubs Securing 50% of ASes on the Internet 47% 36% 24% 17% 53% Average Fraction of Happy ASes lower bound with RPKI results based on simulations on empirical AS-level graphs Improvements in the security 3rd and 2nd models are only 4% and 8% respectively.

  35. Our Methodology • Graph: A UCLA AS-level topology from 09-24-2012 • 39K ASes, 73.5K and 62K customer-provider and peer links • For each attacker-destination pair, simulated routing and determined the sets of doomed and immune ASes • Quantified security-benefit improvements for many different BGPSEC deployment scenarios • Robustness Tests • added 550K extra peering links inferred from IXP data on 09-24-2012 • accounted for traffic patterns by focusing on only certain destinations (e.g. content providers) and attackers • currently repeating all analysis with respect to different local pref models

  36. So Is the Juice Worth the Squeeze? • Unless Security is 1st or BGPSEC deployment is very large, security benefits from partially deployed BGPSEC are meagre • Typically little observable difference between Sec 2nd and 3rd • prevent route manipulations • prevent prefix hijack • Security Benefits or Juice *protocol downgrades collateral damages routing instabilities 4323,2828, FB, prefix SP, 4323, 2828, FB, prefix 2828, FB, prefix BGP and BGPSEC coexistence: very tricky S S S • RPKI (origin authentication) • BGP • BGPSEC

  37. THANK YOU check out the full version at http://arxiv.org/abs/1307.2690 Proofs More empirical analysis and plots Robustness tests BGPSEC deployment guidelines

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