40 results about "Visual cryptography" patented technology

In some embodiments, techniques for voting and visual cryptography may include various enhancements.

In some embodiments, techniques for voting and visual cryptography may include various enhancements.

Systems and methods for creating a visual password are presented. A user having an account or profile is given the option to create a visual password via a graphical user interface. The interface displays a plurality of themes to the user, wherein each theme represents a category of images. The user selects a theme and is presented with a plurality of images within the category. The user selects one or more images in a certain order to create a visual password. The selected images and order of selection are saved as the user's visual password. When the user later attempts to electronically access his account, the user will be required to select the correct pictures in the correct sequence in order to access his account.

The invention provides an identity authentication method realizing a dynamic password encryption mode. The technical scheme comprises the following steps of: I, registering a new user, generating a mask picture M of the new user, and storing the other information and the mask picture M of the new user in a database as the registration information of the new user; II, authenticating the legal identity of the user; if the identity of any user needs authentication, executing the following steps: (1) generating a random cipher; (2) generating a cipher picture; (3) generating a cipher sub-picture;and (4) entering passwords to prove whether the user to be authenticated is a registered user. The invention has the beneficial effects that dynamic passwords can be realized, the decryption mode is simple, and the security is high. In spite of dynamic passwords, cipher transfer is not involved in the authentication process, thus the security is further improved.

The invention discloses a visual cryptography and counterfeit prevention method for hiding and maintaining encrypted image information. The visual cryptography and counterfeit prevention method for patterns comprises the following steps: inputting a confidential image S and migration parameters s and t; randomly generating a grey image R; and subjecting the confidential image S and the random image R to the Exclusive-OR operation to generate an encrypted image E, wherein the encrypted image E contains information of the confidential image S. The confidential image S hidden in the encrypted images E is restored by superposing two encrypted images E, thereby achieving the effect of counterfeit prevention. The visual cryptography and counterfeit prevention method for patterns is incorporatedwith rectangular or arc-shaped anti-counterfeiting icons to form counterfeit-prevention elements which are applied to the data carriers such as counterfeit-prevention files and negotiable securities.The counterfeit-prevention algorithm has the characteristics of easy identification, high difficulty in counterfeiting and the like.

The invention provides an efficient and safe visible anti-copying technique which has low costs. The technique is based on the visual cryptography principles. By printing two sharing pictures of the visual cryptography program on a transparent film with a certain thickness according to a specific way, the cryptic pictures is visible from a certain offset angle instead of from the front of the paper, therefore preventing the pictures from being copied by equipments such as copying machines and scanners. As shown in the following picture, the pictures seen from right above and from the side of the anti-copying transparent film manufactured by the technique of the invention are totally different, wherein the picture can be clearly seen from the side face while the picture can not be seen or can be vaguely seen from the right above. The technique is applicable to the prevention of illegal copying of plane pictures and texts, therefore effectively avoiding forgery; to the prevention of intentionally or unintentionally peeping and covert photography, protecting privacy; and has low cost, applicable to extensively issued plane image-text carriers such as paper money, credit cards, negotiable securities, bills, identity cards and the like.

The invention relates to a method and system for hiding and extracting digital holographic information. The hiding method includes obtaining the information to be hidden; using visual cryptography to expand the pixels of the information to be hidden to obtain multiple visual keys; using a digital holographic imaging system to make each of the visual keys digital A hologram: hiding the digital hologram in different host images according to different attenuation ratios to obtain hidden information. The invention provides a method and system for hiding and extracting digital holographic information, which improves the security and robustness in the process of information transmission.

The invention discloses a non-destructive digital copyright management method for fundus images based on a hybrid structure of fingerprints and zero watermarks. The method first performs 2D-DCT transformation on the normalized fundus images, and extracts features by setting different weights for the transformed coefficients. Highly Discriminative and Robust Fundus Image Features as Fingerprints for Content-Based Retrieval. Then the zero-watermark copyright protection method based on the VSS visual cryptography algorithm establishes the mapping relationship between fingerprints and watermarks for copyright identification. Compared with existing methods, this method has the following advantages: the whole process of the method is non-destructive and meets the requirements of accurate diagnosis; the copyright protection of fundus images is durable, avoiding the one-time problem of digital watermark copyright identification; it is suitable for fundus images The digital rights management method has certain clinical significance for the auxiliary diagnosis of fundus-related diseases.

The invention discloses a grayscale image visual encryption method. In this method, the two processes of image generation and superposition decoding in visual cryptography are placed in an error diffusion feedback loop. That is to say, at the encoder side, each pixel or image block is sequentially processed according to a certain scanning order, and for each pixel or image block on the generated shared image, the superimposed decoding effect is checked immediately, and the superimposed obtained The reconstructed target image is compared with the original secret image to obtain the difference between the two, and the contrast difference is fed back and diffused to surrounding pixels or image blocks that have not been quantified, so as to improve the quality of the decoded and reconstructed secret image. The process of generating shared images, and the synthesis process corresponds to the process of obtaining target images from shared images, the method of the present invention puts synthesis in analysis, that is, analysis based on synthesis.