Summary form only given. Significant work has been performed on encrypting images and compressing images as two separate problems, but traditional encryption techniques generally degrade the compression ratio. To circumvent these issues, two methods have been used. The first employs known encryption algorithms on compressed image data. The second develops compression algorithms which work well for encrypted data. The contribution of this paper is using alpha rooting to perform simultaneous compression and encryption. This achieves improved compression performance in terms of computational complexity and compression ratio. Results are shown for 2 of the well known benchmark images, using the well known JPEG image compression standard to demonstrate the effectiveness of alpha rooting for simultaneous encryption and compression.