Stopping a Rapid Tornado with a Puff

Abstract

RaptorQ is the most advanced fountain code proposed so far. Its properties make it attractive for forward error correction (FEC), offering high reliability at low overheads (i.e., for a small amount of repair information) and efficient encoding and decoding operations. Since RaptorQ's emergence, it has already been standardized by the IETF, and there is the expectation that it will be adopted by several other standardization bodies, in areas related to digital media broadcast, cellular networks, and satellite communications. The paper describes a new attack on RaptorQ that breaks the near ideal FEC performance, by carefully choosing which packets are allowed to reach the receiver. Furthermore, the attack was extended to be performed over secure channels with IPsec/ESP. The paper also proposes a few solutions to protect the code from the attack, which could be easily integrated into the implementations.