SPV: Secure Path Vector Routing for Securing BGP Leonel Ocsa Sáchez

1. SPV: Secure Path Vector Routing for Securing BGP Leonel Ocsa Sáchez leonel.ocsa.sanchez@hotmail.com School of Computer Science

2. Introduction Economy and CriticalInfrastructure Internet BGP Security SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

3. Introduction Border Gateway RoutingProtocol BGP Internet PacketRouting • Trusted enviroment • Minimal Security against attacks SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

4. Introduction S-BGP Secure BGP RoutingProtocol Requieres Computationalefficiency Authenticating of messages Receive a high volumen of messages Internet Routers Burst SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

5. Introduction It’s necessary Public Keys, Private Keys should be minimized for authenticating SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

6. BGP Security Threats SecurePath Vector SPV It’s considered active attackers that actively inject malicious traffic StrongAttackerModel CompromisesRouters in thenetwork • There are two main attack classes: • Denial of Service (DoS) • Falsification Attacks

7. BGP Security Threats - Denial of Service DoS The classic DoS attack is a resource exhaustic attack. The attacker fabricates inputs to evoke the worst-case running time. The attacker can inject malicious TCP packets (TCP poising) Theattackercouldsimplyflood TCP 179 Tostarveoutthe TCP connectionbetweenthetworouters

8. BGP Security Threats – Falsification Attacks The attacker has caused a routing loop

9. Closely Related Work – Hop by Hop Authentication TopreventattacksagainsteBGP TCP Hop by Hop Authentication However the disadvantage is: The falsification of access route cannot be adressed SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

10. Closely Related Work – Securing BGP Updates S-BGP AnAdressSpace PKI AnAssOwnership Certificates ASPATH It´s a sequence of intermediate Ases between source an destination routers that form a direct route for packets to travel. The main Goal of S-BGP: Is to protect the ASPATH and prevent unauthorized advertisements of an IP prefix. SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

11. Securing BGP SPV Removestheneedforroutersperformcomputationallyexpensivepublickeycryptographicoperations and tostoreasymmetricprivatekeys Developsan ASPATH protector Routersneedonlystorethe short-livedprimarykeys SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

12. Securing BGP – Efficient Prefix Ownership Certificates • It works with a smaller blocks service providers. • Service providers often delegate blocks to their costumers. • At each step in the delegation, the recipient of the address block an aymmetric prefix primary key to the represent the block. • The address issuer uses it prefix private key to sign the prefix . SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

13. Securing BGP – Cryptographic Mechanisms This system uses Merkle hash trees. For this it’s posible to use a hash function like MD5 Oneway hash chains Thismakesimpossibleforanattackerto derive values The main property of values of one-way chain is that once the receiver trusts that a value v_i is authentic, it can derive all following values of the chain, so an adversary cannot derive later values. SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

14. Securing BGP – Cryptographic Mechanisms • SPV uses hash trees for three purposes: • To authenticate the values of the single-ASN private key. • To authenticate several single-ASN public keys. • To authenticate de epoch public keys. SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

15. Securing BGP – Basic ASPATH Protector SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

16. Securing BGP – Basic ASPATH Protector SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

17. Securing BGP – Advanced ASPATH Protector SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

18. Evaluation - SPV Security against Attacks For compute the security against signature forgery, and use these results to derive the parameters: n (number of private values per one-time signature) m (number of private values disclosed per one-time signature). This graphic shows the probabilty of a number of attacks to be successfull In particular, the attacker will not have a certificate for the correct prefix The attacker is also generally unable to truncate arbitrary ASPATHs SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

19. Evaluation - Comparison to S-BGP S-BGP SPV • Ensuring that an S-BGP AS cannot be falsely added to the ASPATH. • In S-BGP, threshold cryptogra- phy could be used, wherein peers together generate a key for the non-deploying AS, and use a separate protocol to sign UPDATEs for each other. • S-BGP ensures that each AS on the ASPATH has been transited by the UPDATE, and that ASNs cannot be dropped from the ASPATH. • SPV does not achieve any properties in this case. • In SPV, a single entity computes the private keys, and signs each peer’s ASN into every UPDATE that would be protected by that private key. • In SPV, an attacker controlling two ASes can insert bogus ASNs between its two ASNs. In addition, as an AS receives several UPDATEs from a single prefix, this increment the probability truncate. SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

20. Evaluation - Comparison to S-BGP SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

21. Evaluation – Performance Evaluation Computational Overhead When an AS connects to many peers, the UPDATEs received over one second often take BGP over 100 seconds to process in software SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez When an AS connects to many peers, the UPDATEs received over one second often take BGP over 100 seconds to process in software

22. Conclusions • Secure BGP software implementations enjoy at least a 20-fold speedup over digital signatures • SPV is a protocol leveraging symmetric-key cryptography for securing against the truncation and modification attacks. SPV is configurable to allow tradeoffs between security and CPU usage. • SPV introduces three novel concepts to the design space of se- cure routing protocols: first, it includes private keys within the UPDATEs themselves; second, it does not authenticate the AS that inserts itself onto the path and finally, it provides security not by requiring overwhelming computational complexity • SPV is much faster than S-BGP, so SPV would perform better in periods of high BGP traffic • When replay attacks are considered a threat, SPV allows for shorter timeouts than does S-BGP, and therefore can more effectively secure against replay attacks. SPV: Secure Path Vector Routing for Securing BGP Presented by: Leonel Ocsa Sáchez

23. SPV: Secure Path Vector Routing for Securing BGP Leonel Ocsa Sáchez leonel.ocsa.sanchez@hotmail.com School of Computer Science