Abstract : In this paper, we present some preliminary results on the security of the RadioGatun hash function. RadioGatu has an internal state of 58 words, and is parameterized by the word size, from one to 64 bits. We mostly study the one-bit version of RadioGatun since according to the authors, attacks on this version also affect the reasonably-sized versions. On this toy version, we revisit the claims of the designers and first improve some results. Secondly, iven a differential path, we show how to find a message pair colliding more efficiently than the strategy proposed by the authors using algebraic techniques. We experimented this strategy on the one-bit version since we can efficiently find differential path by brute force. Even though the complexity of this collision attack is higher than the general security claim on RadioGatun<1> , it is still less than the birthday paradox on the size of the internal state.