DARPA plans for Revolutionary approaches for Real-Time Defense against DDoS attacks on Military Networks

As the name suggests, denial-of-service (DoS) attacks are designed to deny legitimate users access to websites and services by overwhelming them with illegitimate connections, requests and traffic.  A distributed denial-of-service attack is when the DoS attacks are being done by multiple attackers all trying to attack a source at once, be it from real hackers or from a single entity and their network of bots.

Such attacks are orchestrated by sets of networked hosts that collectively act to disrupt or deny access to information, communications, or computing capabilities, generally by exhausting targets’ critical resources such as bandwidth, processor capacity, or memory. An attacker uses a non-trivial amount of computing resources, which they either built themselves or, more commonly, by compromising vulnerable PC’s around the world, to send bogus traffic to a site. If the attacker sends enough traffic, legitimate users of a site can’t be serviced.