A new scheme for parallel optical decryption and the display of encrypted image information is presented. The scheme is based on a common path interferometer configuration providing a simple and robust optical setup. Images are encrypted directly during recording by use of a combined phase encoding and phase scrambling method. The encoding and encryption does not require sophisticated, iterative and time consuming optimization algorithms. Pixels are independently encoded and encrypted by use of a simple look-up table technique that can be performed in milliseconds on a standard personal computer. Optical decryption can subsequently be implemented in the common path interferometer by use of single phase or if desired a combined phase/amplitude key. An advantage of the presented method is that the encrypted image may selectively require recording and decryption of phase values or amplitude values or a combination thereof. Another advantage is that decryption is performed in a plane adjacent to the encrypted mask or an equivalent plane whereby generation of speckles in the decrypted image is strongly suppressed. Finally, there is no requirement of positioning a decrypting mask or spatial light modulator in the optical Fourier plane whereby an accurate three dimensional positioning requirement can be avoided.