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Visual Cryptography
Visual cryptography is a cryptographic technique which allows visual information (pictures, text, etc.) to be encrypted in such a way that the decrypted information appears as a visual image. One of the best-known techniques has been credited to Moni Naor and Adi Shamir, who developed it in 1994. They demonstrated a visual secret sharing scheme, where an image was broken up into ''n'' shares so that only someone with all ''n'' shares could decrypt the image, while any shares revealed no information about the original image. Each share was printed on a separate transparency, and decryption was performed by overlaying the shares. When all ''n'' shares were overlaid, the original image would appear. There are several generalizations of the basic scheme including k-out-of-n visual cryptography, and using opaque sheets but illuminating them by multiple sets of identical illumination patterns under the recording of only one single-pixel detector. Using a similar idea, transparencies can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moni Naor
Moni Naor ( he, מוני נאור) is an Israeli Israeli may refer to: * Something of, from, or related to the State of Israel * Israelis, citizens or permanent residents of the State of Israel * Modern Hebrew, a language * ''Israeli'' (newspaper), published from 2006 to 2008 * Guni Israeli ... computer scientist, currently a professor at the Weizmann Institute of Science. Naor received his Ph.D. in 1989 at the University of California, Berkeley. His advisor was Manuel Blum. He works in various fields of computer science, mainly the foundations of cryptography. He is notable for initiating research on public key systems secure against chosen ciphertext attack and creating Malleability (cryptography), non-malleable cryptography, visual cryptography (with Adi Shamir), and suggesting various methods for verifying that users of a computer system are human (leading to the notion of CAPTCHA). His research on Small-bias sample space, give a general framework for combining small k- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adi Shamir
Adi Shamir ( he, עדי שמיר; born July 6, 1952) is an Israeli cryptographer. He is a co-inventor of the Rivest–Shamir–Adleman (RSA) algorithm (along with Ron Rivest and Len Adleman), a co-inventor of the Feige–Fiat–Shamir identification scheme (along with Uriel Feige and Amos Fiat), one of the inventors of differential cryptanalysis and has made numerous contributions to the fields of cryptography and computer science. Education Born in Tel Aviv, Shamir received a Bachelor of Science (BSc) degree in mathematics from Tel Aviv University in 1973 and obtained his Master of Science (MSc) and Doctor of Philosophy (PhD) degrees in Computer Science from the Weizmann Institute in 1975 and 1977 respectively. Career and research After a year as a postdoctoral researcher at the University of Warwick, he did research at Massachusetts Institute of Technology (MIT) from 1977 to 1980 before returning to be a member of the faculty of Mathematics and Computer Science at the Weizma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secret Sharing
Secret sharing (also called secret splitting) refers to methods for distributing a secret among a group, in such a way that no individual holds any intelligible information about the secret, but when a sufficient number of individuals combine their 'shares', the secret may be reconstructed. Whereas ''insecure'' secret sharing allows an attacker to gain more information with each share, ''secure'' secret sharing is 'all or nothing' (where 'all' means the necessary number of shares). In one type of secret sharing scheme there is one ''dealer'' and ''n'' ''players''. The dealer gives a share of the secret to the players, but only when specific conditions are fulfilled will the players be able to reconstruct the secret from their shares. The dealer accomplishes this by giving each player a share in such a way that any group of ''t'' (for ''threshold'') or more players can together reconstruct the secret but no group of fewer than ''t'' players can. Such a system is called a -threshol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One-time Pad
In cryptography, the one-time pad (OTP) is an encryption technique that cannot be cracked, but requires the use of a single-use pre-shared key that is not smaller than the message being sent. In this technique, a plaintext is paired with a random secret key (also referred to as ''a one-time pad''). Then, each bit or character of the plaintext is encrypted by combining it with the corresponding bit or character from the pad using modular addition. The resulting ciphertext will be impossible to decrypt or break if the following four conditions are met: #The key must be at least as long as the plaintext. #The key must be random ( uniformly distributed in the set of all possible keys and independent of the plaintext), entirely sampled from a non-algorithmic, chaotic source such as a hardware random number generator. It is not sufficient for OTP keys to pass statistical randomness tests as such tests cannot measure entropy, and the number of bits of entropy must be at least equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Crypto Animation Demo
The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (the ability to detect and process visible light) as well as enabling the formation of several non-image photo response functions. It detects and interprets information from the optical spectrum perceptible to that species to "build a representation" of the surrounding environment. The visual system carries out a number of complex tasks, including the reception of light and the formation of monocular neural representations, colour vision, the neural mechanisms underlying stereopsis and assessment of distances to and between objects, the identification of a particular object of interest, motion perception, the analysis and integration of visual information, pattern recognition, accurate motor coordination under visual guidance, and more. The n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Do Not Forsake Me Oh My Darling
"Do Not Forsake Me Oh My Darling" is an episode of the allegorical British science fiction TV series, ''The Prisoner''. It was written by Vincent Tilsley and directed by Pat Jackson and was the fourteenth produced. It was the thirteenth episode to be broadcast in the UK on ITV (ATV Midlands and Grampian) on Friday 22 December 1967 and first aired in the United States on CBS on Saturday 3 August 1968. The episode stars Patrick McGoohan as Number Six and features as Number Two, Clifford Evans. Produced while Patrick McGoohan was in America filming ''Ice Station Zebra'', the writers worked around McGoohan's absence by having Number Six's mind implanted in the body of another man ( Nigel Stock), who is then sent out of the Village to help capture a scientist. As a result, McGoohan appears in the episode for only a couple of minutes. The episode title, and the background music heard throughout it, derive from the American song "The Ballad of High Noon" – also called "Do No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Prisoner
''The Prisoner'' is a 1967 British television series about an unnamed British intelligence agent who is abducted and imprisoned in a mysterious coastal village, where his captors designate him as Number Six and try to find out why he abruptly resigned from his job. Patrick McGoohan played the lead role as Number Six. The series was created by McGoohan with possible contributions from George Markstein. Episode plots have elements of science fiction, allegory, and psychological drama, as well as spy fiction. It was produced by Everyman Films for distribution by Lew Grade's ITC Entertainment. A single series of 17 episodes was filmed between September 1966 and January 1968, with exterior location filming in Portmeirion, Wales. Interior scenes were filmed at MGM-British Studios in Borehamwood, north of London. The series was first broadcast in Canada beginning on 5 September 1967, in the UK on 29 September 1967, and in the US on 1 June 1968. Although the show was sold as a thril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grille (cryptography)
In the history of cryptography, a grille cipher was a technique for encrypting a plaintext by writing it onto a sheet of paper through a pierced sheet (of paper or cardboard or similar). The earliest known description is due to the polymath Girolamo Cardano in 1550. His proposal was for a rectangular stencil allowing single letters, syllables, or words to be written, then later read, through its various apertures. The written fragments of the plaintext could be further disguised by filling the gaps between the fragments with anodyne words or letters. This variant is also an example of steganography, as are many of the grille ciphers. Cardan grille and variations The Cardan grille was invented as a method of secret writing. The word ''cryptography'' became the more familiar term for secret communications from the middle of the 17th century. Earlier, the word ''steganography'' was common. The other general term for secret writing was ''cypher'' - also spelt ''cipher''. There is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steganography
Steganography ( ) is the practice of representing information within another message or physical object, in such a manner that the presence of the information is not evident to human inspection. In computing/electronic contexts, a computer file, message, image, or video is concealed within another file, message, image, or video. The word ''steganography'' comes from Greek ''steganographia'', which combines the words ''steganós'' (), meaning "covered or concealed", and ''-graphia'' () meaning "writing". The first recorded use of the term was in 1499 by Johannes Trithemius in his '' Steganographia'', a treatise on cryptography and steganography, disguised as a book on magic. Generally, the hidden messages appear to be (or to be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some implementations of steganography that lack a shared secret are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
