SECRET IMAGE SHARING: A BOOLEAN-OPERATIONS-BASED APPROACH COMBINING BENEFITS OF POLYNOMIAL-BASED AND FAST APPROACHES

In secret image sharing, a polynomial interpolation technique heavy experiences a computation load when the secret image is retrieved later. To the contrary, fast approaches often need larger storage space due to pixel expansion property. This paper proposes a missing-allowable (k, n) scheme which is fast and with a reasonable pixel expansion rate (per). The scheme generates n extremely-noisy shadow images for the given secret color image A, and any k out of these n shadows can recover A loss-freely. In average, to decode a color pixel of A, the retrieval uses only three exclusion-OR operations among 24-bit numbers. Hence, the new method has very fast decoding speed, and its pixel expansion rate is always acceptable (0 < per < 2).