Photon counting imaging and polarized light encoding for secure image verification and hologam watermarking

Abstract

We propose an optical image security scheme based on polarized light encoding and the photon counting technique. An input image is encoded using the concept of polarized light, which is parameterized using Stokes–Mueller formalism. The encoded image is further encrypted by applying the photon counting imaging technique to obtain a photon limited image. For decryption, the photon limited decrypted image is obtained by using a polarized light decoding scheme with the help of appropriate keys. The decrypted image has sparse representation, which contains sufficient information for verification. This photon counted decrypted image can be verified using correlation filters. The proposed encryption technique offers benefits over the double random phase encoding in that it does not require active elements such as a lens and provides flexibility in the design of encryption keys. The proposed encryption scheme has also been used for hologram watermarking. The computer simulation results for secure image verification and the hologram watermarking scheme have been presented.

Cryptographic key distribution over a public network via variance-based watermarking in compressive measurements

“…Since the value is stored in doubles type, i.e., each element takes up 64 bits (8 bytes), our method can detect this kind of tampering with a probability of 52/64 = 81.25%, for the case that only one bit has been falsified. (f)-(i) are the retrieved images with 8,16,32, 64 values of y ′′′ substituted with 0, and with a PSNR of 18.08 dB, 16.88 dB, 14.27 dB, 13.32 dB, respectively. (j) is the reconstructed image with one value missing and all the subsequent data is shifted.…”

“…Based on optical parallel characteristics, it generally uses double spatial light modulators for phase encoding and array charge-coupled devices (CCDs) for recording the intensities [3][4][5][6]. Lately, the DRPE has been integrated with photon-counting to obtain better security and verification performance [7][8][9], but its sampling is still redundant. Fortunately, the newly developed theory of compressed sensing (CS) [10][11][12] provides a new technical solution for DRPE compression during the optical sampling [13], and allows one to accurately reconstruct the signal known a priori to be sparse or compressive from its linear projections, with a sampling rate far below the Nyquist rate [10,11].…”

Optical multiple-image authentication scheme based on the phase retrieval algorithm in gyrator domain

“…In [38], a somewhat complicated information authentication scheme in gyrator domain is reported, in which two amplitude distributions are obtained by encoding each component of the input color image with the inverse Fourier transform, GT, and phase truncation successively, and then encrypted by optical interference of two beams. By making using of a photon-counting technique, Rajput et al [39] proposed a secure image verification scheme where the input image is first encoded using polarized light, while Markman et al [40] suggested an optical security approach for object authentication where the compressed data is stored inside a phase-encoded quick response (QR) code. To enhance DRPE security, Chen and Chen [41] encrypted the original image into only a compressed phase distribution via phase reservation and compression.…”

Securing information using optically generated biometric keys

“…On the other hand, different types of optical encryption schemes have also been reported in the area of information security using the joint transform correlator [20], interference [21] and digital holography [22][23][24][25][26][27][28][29]. The reported techniques based on digital holography are widely used for image authentication and data security [24][25][26][27]. This is the process of recording a hologram by using a charge-coupled device (CCD), and the hologram is numerically reconstructed [22].…”