Summary: Lydia Sidrak
A DoS-limiting Network Architecture
Ziaowei Yang, David Wetherall, Thomas Anderson
Authors of this paper propose an architecture designed to limit Denial of Service attacks on open,
Internet-like networks. Traffic Validation Architecture (TVA) allows the destination to control
what traffic it receives via capabilities, which are not forgeable, are processed by the routers
(without trusting hosts), and also achieved with low processing cost.
To ensure attacker requests don't bully legitimate request, path-identifier queueing is used.
Destination policies depend on role of host in network. Clients may accept a request if it matches
an outgoing request. Servers can "cautiously" accept all requests, but blacklist misbehaving
senders in the event of unexpected or flooded packets.
Routers compute pre-capabilities that contain source and destination IPs, a timestamp and a secret
key. This serves as a sort of "message authentication" enforcing unforgeability and "time limit"
Routers that process packets only keep state for flows trying to reach N/T bandwidth
There may be reduced efficiency when there are short flows near host, like in root DNS servers,
but this can be addressed if more request bandwidth is allotted.
A minor point: though "more sophisticated" policies such as CAPTCHA and HTTP cookies are