Efficient and Universal Corruption Resilient Fountain Codes

TL;DR

This paper introduces a new family of fountain codes resilient to adversarial errors, using information-theoretic techniques to ensure reliable data transmission without secret channels, suitable for decentralized and distributed scenarios.

Contribution

The paper develops a novel class of corruption-resilient fountain codes that extend LT and Raptor codes, with efficient decoding and applicability to distributed computing.

Findings

Codes are robust against adversarial packet corruption.

Decoding can be performed efficiently with both exhaustive and practical algorithms.

Codes operate effectively without secret channels or prior knowledge of adversary strength.

Abstract

In this paper, we present a new family of fountain codes which overcome adversarial errors. That is, we consider the possibility that some portion of the arriving packets of a rateless erasure code are corrupted in an undetectable fashion. In practice, the corrupted packets may be attributed to a portion of the communication paths which are controlled by an adversary or to a portion of the sources that are malicious. The presented codes resemble and extend LT and Raptor codes. Yet, their benefits over existing coding schemes are manifold. First, to overcome the corrupted packets, our codes use information theoretic techniques, rather than cryptographic primitives. Thus, no secret channel between the senders and the receivers is required. Second, the encoders in the suggested scheme are oblivious to the strength of the adversary, yet perform as if its strength was known in advance. Third, the sparse structure of the codes facilitates efficient decoding. Finally, the codes easily fit a decentralized scenario with several sources, when no communication between the sources is allowed. We present both exhaustive as well as efficient decoding rules. Beyond the obvious use as a rateless codes, our codes have important applications in distributed computing.