Final Activity Report Summary - CRYPTOSENSORS (Cryptographic security of wireless sensor networks)
This project concerned the applications of cryptography in the area of the wireless sensor networks (WSNs). WSNs are a new technology that can be used in building monitoring, burglar alarms, military applications, border control, etc. WSNs consist of a large number of intelligent nodes which are low-cost, low-power and small. Because of these properties a special care must be taken in the design of the protocols for such networks. Namely, one has to constrain the number of processor cycles and the number of radio-transmitted bits (since this costs energy), and one often cannot assume that the nodes do not leak any information about its state (in other words: they are not leakage-resilient). Because of these limitations many standard cryptographic protocols cannot be used in WSNs. This is especially true about the protocols based on the public-key cryptography (which is often too energy consuming). For example, the classical (public-key-based) methods for the key distribution cannot be used in WSNs.
In this project we were particularly interested in the active security of sensor networks, i.e. security in a model where the adversary not only eavesdrops, but also actively disturbs the communication. The work performed by us is as follows. First, we gave a formal analysis of the active security of the existing key-distribution schemes for the sensor networks, and we provided a comparison between them. We concluded that the best scheme in this context is the one based on the method of Blom (1984). Second, we proposed a new method for secure aggregation in the sensor networks, which has increased resiliency against the active attacks. Third, we proposed a new, formal model, for increasing leakage-resiliency of cryptographic protocols, and implemented some basic cryptographic primitives (secret-sharing, stream cipher) in this model. This method is based on so-called Bounded-Retrieval Model, where the adversary is allowed to retrieve any information about the internal state of the machine, as long as the total length of the retrieved data is bounded
In this project we were particularly interested in the active security of sensor networks, i.e. security in a model where the adversary not only eavesdrops, but also actively disturbs the communication. The work performed by us is as follows. First, we gave a formal analysis of the active security of the existing key-distribution schemes for the sensor networks, and we provided a comparison between them. We concluded that the best scheme in this context is the one based on the method of Blom (1984). Second, we proposed a new method for secure aggregation in the sensor networks, which has increased resiliency against the active attacks. Third, we proposed a new, formal model, for increasing leakage-resiliency of cryptographic protocols, and implemented some basic cryptographic primitives (secret-sharing, stream cipher) in this model. This method is based on so-called Bounded-Retrieval Model, where the adversary is allowed to retrieve any information about the internal state of the machine, as long as the total length of the retrieved data is bounded
