Security, Privacy and Abuse Prevention

Let H be a class of boolean functions and consider a composed class H' that is derived from H using some arbitrary aggregation rule (for example, H' may be the class of all 3-wise majority-votes of functions in H). We upper bound the Littlestone dimension of H' in terms of that of H. As a corollary, we derive closure properties for online learning and private PAC learning. The derived bounds on...

We study the sample complexity of learning threshold functions under the constraint of differential privacy. It is assumed that each labeled example in the training data is the information of one individual and we would like to come up with a generalizing hypothesis while guaranteeing differential privacy for the individuals. Intuitively, this means that any single labeled example in the...

Despite many successes in combating web identity theft and website impersonation, websites with fraudulent identities continue to harm Internet users. Only the fully qualified domain name in the URL gives users the unfalsifiable identity information they need to make a trust decision. Unfortunately, URLs are complex and users must decide whether to follow them from within browsers, messaging...

This document defines a method (serve-stale) for recursive resolvers to use stale DNS data to avoid outages when authoritative nameservers cannot be reached to refresh expired data. One of the motivations for serve-stale is to make the DNS more resilient to DoS attacks and thereby make them less attractive as an attack vector. This document updates the definitions of TTL from RFCs 1034 and 1035...