
The Internet routing security story of the past decade has largely been about fixing route origins. RPKI Route Origin Validation (ROV) gave operators a cryptographic way to verify that the AS announcing a prefix was actually authorized to do so. That work has now reached majority coverage, with over half of all IPv4 and IPv6 routes now protected by Route Origin Authorizations (ROAs).
But origin validation only tells you where a route claims to start. It says nothing about the path it took to get to you. A route can have a perfectly valid origin and still arrive via a completely illegitimate chain of ASes, through a misconfigured transit network, a malicious route leak, or a manipulated AS_PATH. This gap is exactly what ASPA (Autonomous System Provider Authorization) is designed to close.
ASPA has moved from theory into early operational deployment, even though the core ASPA profile and verification work remain in IETF draft form as of March 2026. ARIN and RIPE NCC both support ASPA object creation in production. Major networks have begun deploying ASPA validation globally. Router implementations exist in BIRD and OpenBGPD. This article is intended to explain what ASPA is, how it works technically, what it Continue reading