Forward-Secure Sequential Aggregate Authentication

Wireless sensors are employed in a wide range of applications. One common feature of most sensor settings is the need to communicate sensed data to some collection point or sink. This communication can be direct (to a mobile collector) or indirect – via other sensors towards a remote sink. In either case, a sensor might not be able to communicate to a sink at will. Instead it collects data and waits (for a potentially long time) for a signal to upload accumulated data directly. In a hostile setting, a sensor may be compromised and its post-compromise data can be manipulated. One important issue is forward security – how to ensure that pre-compromise data cannot be manipulated? Since a typical sensor is limited in storage and communication facilities, another issue is how to minimize resource consumption due to accumulated data. It turns out that current techniques are insuf£cient to address both challenges. To this end, we explore the notion of Forward-Secure Sequential Aggregate (FssAgg) authentication Schemes. We consider FssAgg authentication schemes in the contexts of both conventional and public key cryptography and construct a FssAgg MAC scheme and a FssAgg signature scheme, each suitable under different assumptions. This work represents the initial investigation of Forward-Secure Aggregation and, although the proposed schemes are not optimal, it opens a new direction for follow-on research.