The SCION Next-Generation Network (NGN) architecture has expanded steadily since 2017, with today 20+ ISPs offering SCION connectivity. In production, IP-to-SCION-to-IP translation by SCION-IP-Gateways (SIGs) is used, such that applications are unaware of the NGN communication. To accelerate innovation and deployments, our aim is to increase the number of native SCION use cases, where the application is fully SCION-aware and optimizes communication across all path choices offered by the network. We set out to achieve two core objectives: (1) facilitating simple native connectivity for applications, and (2) enhancing the scalability of SCION deployment at academic sites.

Path validation promises a necessary security add-on for future Internet architectures. It authenticates not only source identities but also the exact path where a packet forwards through. This offers users more flexibility and reliability in network services. Most existing solutions focus on single-path validation that pre-correlates a packet to a specific forwarding path. However, parallel transmissions in multipath routing tend to induce bursty traffic that is hardly validated in time by existing solutions. In this paper, we present SwiftParade as the first attempt toward anti-burst multipath validation. It proposes a composite validation technique that can simultaneously validate a group of packets likely from multiple different paths. This helps to amortize the validation overhead across packets of the entire group instead of imposing the validation overhead equally on every packet. To implement composite validation, SwiftParade further explores a noncommutative homomorphic asymmetric encryption scheme. We prove effectiveness and security of SwiftParade through theoretical analysis. We also conduct extensive experiments to evaluate SwiftParade performance. The results show that SwiftParade offers high efficiency and applicability to multipath validation with complex routing topologies. In comparison with the state-of-the-art multipath validation solution—Atlas, SwiftParade speeds up packet processing by 2.5×$\sim 8.3\times$and increases communication throughput by 2.8×$\sim 10.2\times$.

Path validation has already been incrementally deployed in the Internet architecture. It secures packet forwarding by enabling end hosts to negotiate specific forwarding paths and enforcing on-path routers to prove their forwarding behaviors along these paths. Most existing path validation solutions target static paths, paying less attention to fully dynamic paths that support flexible routing. In this paper, we present Hummingbird as the first validation solution over fully dynamic paths. It features a hidden equal-probability sampling technique. Gaining efficiency via routers probabilistically sampling packets to validate, we craft the sampling probability such that each router validates a similar amount of packets given an unknown path length. We further hide the state of whether a packet has been sampled and validated using a lightweight, non-cryptographic scheme. This prevents attackers from differentiating and selectively mis-forwarding packets. We validate security and efficiency of Hummingbird through both theoretical proof and experimental evaluation.

Path validation has been explored as an indispensable security feature for the future Internet. Motivated by the Path-Aware Networking Research Group (PANRG) under the Internet Engineering Task Force (IETF) and Internet Research Task Force (IRTF), it gives end-hosts more control over packet forwarding and ensures that the forwarding history is verifiable. The main idea is to require that routers add proofs in packet headers for other routers to verify. We identify linear-scale proofs as the essential efficiency barrier of existing path validation solutions. In this paper, we propose Atomos to validate network paths with constant-size proofs. To this end, we construct a noncommutative homomorphic asymmetric-key encryption scheme. Asymmetric cryptography minimizes the number of proofs needed and saves time in processing proofs. The homomorphism we design yields constant-size proofs. It limits the header-space overhead and outperforms existing linear-scale counterparts when the path length exceeds a value that is usually small. Furthermore, the proposed encryption scheme is noncommutative so that any deviation from the forwarding path can be detected. We explore a series of design strategies for security and efficiency. The evaluation results show that Atomos yields not only shorter proofs but also faster validation than existing solutions.