Preventing massive automated access to web resources

Automated web tools are used to achieve a wide range of different tasks, some of which are legal activities, whilst others are considered attacks to the security and data integrity of online services. Effective solutions to counter the threat represented by such programs are therefore required. In this work, we present MosaHIP, a Mosaic-based Human Interactive Proof (HIP), which is able to prevent massive automated access to web resources. Properties of the proposed solution grant an improved security over usual text-based and image-based HIPs, whereas the user-friendliness of the system alleviates the user from the discomfort of typing any text before accessing to a web content. Experimental evidence of the effectiveness of the proposed technique is given by submitting our system to a series of tests simulating possible bot attacks.