A broad API designed to allow various workflows enables implementing watermarking schemes of all kinds.
Simple configuration with YAML and easy scripting using Lua; Waterfall is designed to make implementation a breeze.
Every instance of Waterfall acts as an independent node on the network, allowing for significant scalability.
From policy to packets
Waterfall separates traffic-watermarking logic from the infrastructure around it. Describe when a scheme should run in YAML, implement its embedder and detector as Lua capsules, and let the runtime handle flow discovery, packet monitoring, traffic actions, timing, peer communication, keys, and correlation.
When matching traffic satisfies a policy trigger, Waterfall starts a dedicated capsule for that flow. Capsules can bind related flows, coordinate across nodes, and submit extracted keys or measurements as structured JSON.
See the configuration modelOne runtime, two roles
Every scheme uses the same flow-aware runtime while exposing the operations appropriate to its role.
Embedding capsule
Load key material and change packet handling under Lua control to encode the watermark a scheme requires.
Detection capsule
Observe matching traffic, derive a key or measurement, and send the result to Waterfall's correlation service.
local wf = require("waterfall") -- import waterfall module
local seconds = wf.get_parameter("timeout_s") -- retrieve parameter defined in policy
local timeout = seconds * wf.SECOND -- provided constants can be used to create time values
local previous = nil -- time of last packet
local ipds = {} -- inter-packet delays
wf.on_packet("measure", "DataFlow", function() -- runs for each packet
local now = wf.get_watermark_time() -- get the current time (relative to watermark start)
if previous then
table.insert(ipds, now - previous) -- save inter-packet delay
end
previous = now -- update time of last packet
end)
wf.on_timeout("stop", timeout, function () -- schedules the timeout
wf.submit_data("exampleScheme", "ipds", ipds) -- submit ipds to correlation service
wf.stop() -- stop the capsule
end)Lua-native schemes
Capsule scripts import one module. Configuration and manifests provide experiment values without rebuilding the runtime, while the API exposes the operations schemes need.