40 results about "Visual cryptography" patented technology

An embodiment of the invention discloses a display method and a display device of a peeping-preventing visible code. The method includes receiving at least one code input into a code input box by a user; selecting and displaying a color of the code and a background color; respectively adjusting the color of the code and the background color into a preset range, and obtaining the peeping-preventing visible code which is visible in a preset distance range; and displaying the peeping-preventing visible code through the code input box. As the user can see the correctness of the input code when inputting the code, if the user finds wrong inputting, the user can correct the code immediately, the problem that a wrong code is submitted to cause time waste is resolved, and meanwhile safety of the code is improved. Meanwhile, as the input code only can be seen at short range, and the code cannot be seen clearly at a long distance, a certain function of code peeping prevention is achieved.

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

The invention provides a one-time pad password system based on visual cryptography. The technical scheme is that the one-time pad password system comprises a main-control module, an identity characteristic input interface, a visual information display terminal, a password input terminal and a plurality of subscriber masking pictures, wherein each subscriber masking picture corresponds to a subscriber; the identity characteristic input interface receives the identity characteristic data input of subscribers and sends the identity characteristic data input to the main-control module; the password input terminal receives the password input and sends the password input to the main-control module; the visual information display terminal receives visual cryptography subsidiary pictures sent by the main-control module and displays the visual cryptography subsidiary pictures to the subscribers; the subscribers place the possessed subscriber masking pictures on a first aligning frame to acquire the password P at the time; the main-control module comprises a master control program and a database; the main-control module takes a computer system as the platform and further comprises another master control program and another database to achieve subscriber register and authentication identification. The one-time pad password system provided by the invention can achieve safe, convenient andefficient subscriber identity authentication.

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

The invention relates to a digital holographic information hiding and extracting method and system. The hiding method comprises the steps of obtaining to-be-hidden information; performing pixel expansion on the to-be-hidden information by using visual cryptography to obtain a plurality of visual keys; utilizing a digital holographic imaging system to make each visual secret key into a digital hologram; and hiding the digital hologram in different host images according to different attenuation proportions to obtain hidden information. According to the digital holographic information hiding andextracting method and system provided by the invention, the safety and robustness in the information transmission process are improved.

The invention relates to an information security technology combining visual cryptography and a photochromic material. The technology is characterized in that the technology is based on the visual cryptography principle, one of information subgraphs generated by a visual cryptography scheme is printed into a certain substrate carrier through the photochromic material which has certain selectivityto laser parameters, another generated information subgraph is printed onto a transparent and visible carrier material, the transparent carrier material is calibrated and aligned with the substrate carrier, laser beams of specific parameters are used for illuminating, and finally original information can be decrypted and seen by human eyes. The technology has the advantages that the photochromic material is used for printing the image information of the visual cryptography, the safety and practicality of optical information are increased, and the technology is applicable to fields such as illegal copying preventing, copyright protection, information encryption and hiding and identity authentication.

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.