Cryptographic techniques for encrypting images, and decrypting and reconstructing images, are provided to facilitate preventing unauthorized access to images. A holographic cryptographic component (HCC) can generate a global image comprising a scaled version of a source image and random content, generate a phase hologram representing the global image, and encrypt the phase hologram to generate an encrypted hologram based on a random phase mask, which can be the private encryption key. To reconstruct the source image, an HCC can overlay a phase mask, which can be a conjugate of the random phase mask, on the encrypted hologram to decrypt it, and can illuminate the decrypted hologram with a coherent light source. The source image is only reconstructed properly if the correct phase mask is used. If HCC applies the encryption process repetitively to the same source image, HCC can generate a different encrypted hologram in each run.