Abstract
This paper proposes a secret image sharing scheme based on only ADDITION operation to embed a grey level or colour secret image into two or more shadow images. In this scheme, the secret image cannot be reconstructed until all the shadow images have been collected. The secret image can be losslessly recovered. Since only ADDITION operation is used in both creating the shadow images and recovering the secret image, it can be easily and quickly implemented so that this property is very important for many embedded systems, i.e. mobile equipments.