Abstract: A dynamic access pricing and active countermeasure system and method for detecting and protecting against automated Internet attackers that incapacitates or disables the attackers. The dynamic access pricing and active countermeasure generally includes 1) the provision of a device fingerprint by a device at the start of an iteration of the client-puzzle challenge-response protocol; 2) a dynamic access pricing policy associated with a transaction identifier; 3) the determination of the puzzle difficulty level based on the interaction history of the device fingerprint solely with respect to the dynamic access pricing policy; 4) the binding of the device fingerprint to the client puzzle challenge; the generation of transaction authorization codes that the device presents to a protected application, system, interface or device.

Abstract: Systems and methods for classification of internet devices for classifying devices on the Internet as either hostile or benign. Hostile devices are those that are or will be engaging in denial of service attacks.