Computational Complexity of Traffic Hijacking under BGP and S-BGP

TL;DR

This paper analyzes the computational difficulty of traffic hijacking under BGP and S-BGP, revealing that hijacking is polynomial-time solvable in BGP but NP-hard in S-BGP, highlighting the security implications of protocol differences.

Contribution

It proves that traffic hijacking is NP-hard under S-BGP, contrasting with polynomial-time solvability under BGP, and clarifies when hijacking equates to interception in S-BGP.

Findings

Hijacking is polynomial-time solvable in BGP.

Hijacking is NP-hard in S-BGP.

Conditions when hijacking equals interception in S-BGP.

Abstract

Harmful Internet hijacking incidents put in evidence how fragile the Border Gateway Protocol (BGP) is, which is used to exchange routing information between Autonomous Systems (ASes). As proved by recent research contributions, even S-BGP, the secure variant of BGP that is being deployed, is not fully able to blunt traffic attraction attacks. Given a traffic flow between two ASes, we study how difficult it is for a malicious AS to devise a strategy for hijacking or intercepting that flow. We show that this problem marks a sharp difference between BGP and S-BGP. Namely, while it is solvable, under reasonable assumptions, in polynomial time for the type of attacks that are usually performed in BGP, it is NP-hard for S-BGP. Our study has several by-products. E.g., we solve a problem left open in the literature, stating when performing a hijacking in S-BGP is equivalent to performing an interception.