Abstract: Recently, a variety of chaos-based hash functions have been proposed. Nevertheless, none of them works efficiently in parallel computing environment. In this Letter, an algorithm for parallel keyed hash function construction is proposed, whose structure can ensure the uniform sensitivity of hash value to the message. By means of the mechanism of both changeable-parameter and self-synchronization, the keystream establishes a close relation with the algorithm key, the content and the order of each message block. The entire message is modulated into the chaotic iteration orbit, and the coarse-graining trajectory is extracted as the hash value. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function. It is simple, efficient, practicable, and reliable. These properties make it a good choice for hash on parallel computing platform. [Copyright &y& Elsevier]