Certificate Transparency (CT) relies on a gossip mechanism to detect logs that present conflicting versions of its structure and content to different parties; so called split views. We propose a retrospective and application neutral approach towards gossip that is based on client-initiated log communications in plaintext using an existing infrastructure of packet processors, e.g., including routers, network interface cards, and operating systems.
The idea is that clients interact with the logs over a network, and as part of the network in-line packet processors aggregate observed responses to off-path challengers that periodically verify log consistency. Conceptually it would be nice to aggregate at packet processor which see diverse traffic, including those that are located at well-connected Autonomous Systems (ASes). Based on a simulation using RIPE Atlas probes from 3500 unique ASes, we show that our approach towards gossip provide significant protection against many relevant attackers with relatively little opt-in and in incremental deployment scenarios. We implemented in-line aggregation that runs at packet processors supporting P4 and XDP, showing that up to 10 Gbps line speed can be achieved on two different hardware targets.
Further details on the estimated impact of deployment and our proof-of-concept
implementations can be found in the ripe, p4bmv2 and xdp directories.
https://arxiv.org/pdf/1806.08817.pdf
Specified in the respective subdirectories separately