"It is unclear how effective [Project Shield] would be against Application Layer DoS attacks, where web servers are flooded with HTTP requests. These represent more leveraged DoS attacks, requiring less infrastructure on the part of the attacker, but are still fairly simplistic. If the DDoS protection provided operates at the application layer, then it could help," Ghosemajumder said.
"What it would not protect against is Advanced Denial of Service attacks, where the attacker uses knowledge of the application to directly attack the origin server, databases, and other backend systems which cannot be protected against by a CDN and similar means."
Google hasn't mentioned directly the number of sites currently being protected by Project Shield, so there is no way to measure the effectiveness of the program form the outside.
In related news, Google also released a second DDoS related tool on Monday, which is possible thanks to data collected by Arbor networks. The Digital Attack Map, as the tool is called, is a monitoring system that allows users to see historical DDoS attack trends, and connect them to related news events on any given day. The data is also shown live, and can be granularly sorted by location, time, and attack type.
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