Abstract-We address the problem of pollution attacks in coding based distributed storage systems. In a pollution attack, the adversary maliciously alters some of the stored encoded packets, which results in the incorrect decoding of a large part of the original data upon retrieval. We propose algorithms to detect and recover from such attacks. In contrast to existing approaches to solve this problem, our approach is not based on adding cryptographic checksums or signatures to the encoded packets, and it does not introduce any additional redundancy to the system. The results of our analysis show that our proposed algorithms are suitable for practical systems, especially in wireless sensor networks.Index Terms-Network level security and protection, sensor networks, distributed data storage, network coding, pollution attack, integrity protection

Abstract-We present a novel information theoretic approach to make network coding based storage secure against pollution attacks in sensor networks. The approach is based on a new decoding algorithm which makes it possible to find adversarial blocks using one more encoded block than strictly necessary for decoding. Our scheme fits well to the requirements of sensor networks, because it operates with adding very low computational and communication overhead to source and storage nodes, only the collector node needs to perform some additional computation. Our approach does not apply cryptography, hence it works in environments where no pre-shared keys, secure channels or PKI are available, which is often the case in sensor networks.

Abstract-The application of network coding can significantly improve the performance of message delivery in delay tolerant networks, assuming all participants behave honestly. However, if some nodes of the network are compromised, the adversary can launch pollution attack and this way can destroy large amount of data with small effort. Current solutions against pollution attack require public key infrastructure, that is often not available in mobile ad-hoc networks. Our proposal allows packets to verify each other, hence an intermediate node can decide whether these packets can be encoded together without authenticating the source.Index Terms-Network level security and protection, network coding, pollution attack, integrity protection, delay tolerant networks.