We propose a simple and efficient hash function based on programmable elementary cellular automata. Cryptographic hash functions are important building blocks for many cryptographic protocols such as authentication and integrity verification. They have recently brought an exceptional research interest, especially after the increasing number of attacks against the widely used functions as MD5, SHA-1 and RIPEMD, causing a crucial need to consider new hash functions design and conception strategies. The proposed hash function is built using elementary cellular automata that are very suitable for cryptographic applications, due to their chaotic and complex behavior derived from simple rules interaction. The function is evaluated using several statistical tests, while obtained results demonstrate very admissible cryptographic proprieties such as confusion, diffusion capability and high sensitivity to input changes. Furthermore, the hashing scheme can be easily implemented through software or hardware, and provides very competitive running performances.