Much like most other problems in technology, securing the reachability (routing) information in the internet core as much or more of a people problem than it is a technology problem. While BGP security can never be perfect (in an imperfect world, the quest for perfection is often the cause of a good solution’s failure), there are several solutions which could be used to provide the information network operators need to determine if they can trust a particular piece of routing information or not. For instance, graph overlays for path validation, or the RPKI system for origin validation. Solving the technical problem, however, only carries us a small way towards “solving the problem.”
One of the many ramifications of deploying a new system—one we do not often think about from a purely technology perspective—is the legal ramifications. Assume, for a moment, that some authority were to publicly validate that some address, such as 2001:db8:3e8:1210::/64, belongs to a particular entity, say bigbank, and that the AS number of this same entity is 65000. On receiving an update from a BGP peer, if you note the route to x:1210::/64 ends in AS 65000, you might think you are safe in using this path to reach destinations located in bigbank’s network.
What if the route has been hijacked? What if the validator is wrong, and has misidentified—or been fooled into misidentifying—the connection between AS65000 and the x:1210::/64 route? What if, based on this information, critical financial information is transmitted to an end point which ultimately turns out to be an attacker, and this attacker uses this falsified routing information to steal millions (or billions) of dollars?
Who is responsible? This legal question ultimately plays into the way numbering authorities allow the certificates they issue to be used. Numbering authorities—specifically ARIN, which is responsible for numbering throughout North America—do not want the RPKI data misused in a way that can leave them legally responsible for the results. Some background is helpful.
The RPKI data, in each region, is stored in a database; each RPKI object (essentially and loosely) contains an origin AS/IP address pair. These are signed using a private key and can be validated using the matching public key. Somehow the public key itself must be validated; ultimately, there is a chain, or hierarchy, of trust, leading to some sort of root. The trust anchor is described in a file called the Trust Anchor Locator, or TAL. ARIN wraps access to their TAL in a strong indemnification clause to protect themselves from the sort of situation described above (and others). Many companies, particularly in the United States, will not accept the legal contract involved without a thorough investigation of their own culpability in any given situation involving misrouting traffic, which ultimately means many companies will simply not use the data, and RPKI is not deployed.
The essential point the paper makes is: is this clause really necessary? Thy authors make several arguments towards removing the strict legal requirements around the use of the data in the TAL provided by ARIN. First, they argue the bounds of potential liability are uncertain, and will shift as the RPKI is more widely deployed. Second, they argue the situations where harm can come from use of the RPKI data needs to be more carefully framed and understood, and how these kinds of legal issues have been used in the past. To this end, the authors argue strict liability is not likely to be raised, and negligence liability can probably be mitigated. They offer an alternative mechanism using straight contract law to limit the liability to ARIN in situations where the RPKI data is misused or incorrect.
Whether this paper causes ARIN to rethink its legal position or not is yet to be seen. At the same time, while these kinds of discussions often leave network engineers flat-out bored, the implications for the Internet are important. This is an excellent example of an intersection between technology and policy, a realm network operators and engineers need to pay more attention to.