An approach between chaotic behaviour and image indexing is proposed in this paper. A data-base is ciphered, image by image, by using Rössler Map. The image cryptograms are indexed with different methods: colour histogram, auto-correlogram, Color Co-occurrence Matrix (CCM) or Modified Colour Co-occurrence Matrix (MCCM). The experiments will show that the cryptograms stored are quite the same, so the eavesdropper cannot find any information by looking at a specific cryptogram.