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Examines paparazzi and copyright law, regulation of the Internet, the European Union Database Directive and U.S. efforts to change database laws, Tasini v. The New York Times, freedom of information and access to public sector information, company law and e-mail messages, electronic commerce, cryptography export controls, domain names and trade marks, censorship, and limited copying. (PEN)

Demonstrates the use of technology to enhance the appreciation of applications involving abstract algebra. The symbolic manipulator Maple can perform computations required for a linear cryptosystem. One major benefit of this process is that students can encipher and decipher messages using a linear cryptosystem without becoming confused and frustrated with the many intermediate computations involved. (Author/PVD)

Presents an historical overview of Vannevar Bush's efforts to develop a machine for free-form indexing and computerized information retrieval. Descriptions of the Memex concept and two related machines--the Rapid Selector and the Comparator--are provided; and the shift in emphasis to a device for business or cryptanalytic purposes is discussed. (93 references) (LRW)

Described are activities in the study of techniques used to conceal the meanings of messages and data. Some background information and two BASIC programs that illustrate the algorithms used in a new cryptographic system called "public-key cryptography" are included. (CW)

Discusses issues related to computer security, including confidentiality, integrity, and authentication or availability; and presents a selected list of Web sites that cover the basic issues of computer security under subject headings that include ethics, privacy, kids, antivirus, policies, cryptography, operating system security, and biometrics. (LRW)

Linear ciphers, substitution ciphers, public-key cryptosystems, and trapdoor knapsacks are each discussed. (MNS)

Explores the use of computers for teaching mathematical models of transposition ciphers. Illustrates the ideas, includes activities and extensions, provides a mathematical model and includes computer programs to implement these topics. (MVL)

Discussed is an application of number theory to cryptology that can be used with secondary school students. Background on the topics is given first, followed by an explanation for use of the topic. (MNS)

Reviews four books dealing with the following topics: astronomy, computers, cryptology, and physics. (AEA)

The Public Cryptography Study Group accepted the claim made by the National Security Agency that some information in some publications concerning cryptology could be inimical to national security, and is allowing the establishment of a voluntary mechanism, on an experimental basis, for NSA to review cryptology manuscripts. (MLW)

An average-case variant of the k-SUM conjecture asserts that finding k numbers that sum to 0 in a list of r random numbers, each of the order rk, cannot be done in much less than \(r^{\lceil k/2 \rceil }\) time. However, in the dense regime of parameters, where the list contains more numbers and many solutions exist, the complexity of finding one of them can be significantly improved by Wagner's k-tree algorithm. Such algorithms for k-SUM in the dense regime have many applications, notably in cryptanalysis. In this article, assuming the average-case k-SUM conjecture, we prove that known algorithms are essentially optimal for k= 3,4,5. For k> 5, we prove the optimality of the k-tree algorithm for a limited range of parameters. We also prove similar results for k-XOR, where the sum is replaced with exclusive or. Our results are obtained by a self-reduction that, given an instance of k-SUM that has a few solutions, produces from it many instances in the dense regime. We solve each of these instances using the dense k-SUM oracle and hope that a solution to a dense instance also solves the original problem. We deal with potentially malicious oracles (that repeatedly output correlated useless solutions) by an obfuscation process that adds noise to the dense instances. Using discrete Fourier analysis, we show that the obfuscation eliminates correlations among the oracle's solutions, even though its inputs are highly correlated. [ABSTRACT FROM AUTHOR]

With the development of science and technology and the appearance of various special conditions that cause signers to be unable to sign, proxy signature is gradually becoming a hot spot in cryptography research. This paper combines proxy signature, quantum teleportation, and multi-party verification and proposes a multi-party verifiable quantum proxy signature scheme based on quantum teleportation. This scheme has the following characteristics: The authentication method based on the H a s h function can effectively solve the problem of identity identification among members; in order for the proxy signer to be able to verify the correctness of the proxy authorization, a form of proxy signature authorization that concatenates the identity information of the original signer is used. The security analysis shows that our scheme is unforgeable and undeniable and can resist intercept-resend attacks and cheating attacks. [ABSTRACT FROM AUTHOR]

The article focuses on the 1943 American military operation "Operation Vengeance," which sought to kill Japanese Admiral Isoroku Yamamoto during the Solomon Islands campaign of World War II. The author discusses how Allied codebreaking was in jeopardy because of this mission and examines several published works that reflect on or avoid the event, including "Islands of Destiny," by John Prados, "Operation Vengeance," by Dan Hampton, and "We Killed Yamamoto," by Si Sheppard.

We numerically demonstrate that a pure time-harmonic bias AC current of a specific amplitude τ f and angular frequency ω f can excite the chaotic magnetization dynamics in a Josephson-like antiferromagnetic (AFM) spin Hall oscillator (SHO) with biaxial magnetic anisotropy of an AFM layer. The nature of such a stochastic generation regime in a Josephson-like AFM SHO could be explained by the random hopping of the working point of the SHO between several quasi-stable states under the action of an applied AC current. We reveal that depending on the ω f / τ f ratio several stochastic generation regimes interspersed with regular generation regimes can be achieved in an AFM SHO, which can be used in spintronic random signal sources and various nano-scale random signal devices, including the spintronic p-bit device considered in this work. The obtained results are important for the development and optimization of spintronic devices capable of generating and processing (sub-)THz-frequency random signals, which are promising for ultra-fast probabilistic computing, cryptography, secure communication, etc. [ABSTRACT FROM AUTHOR]

With the continuous advancement of information technology, the security of digital images is becoming increasingly important. To ensure the secure transmission of images, this paper proposes an image encryption algorithm based on a two-dimensional dual discrete quadratic chaotic map (2D-DDQCM). The digital sequences generated by the 2D-DDQCM exhibit high randomness and unpredictability, making them suitable as pseudo-random number generators in cryptography. In the first round of encryption, the algorithm generates an initial key using natural noise and transforms the pixel positions and values of the image using a pseudo-random key stream generated by the 2D-DDQCM, achieving confusion and diffusion. To ensure the security of the encryption process, the algorithm employs a feedback key mechanism, which ensures the dynamism and unpredictability of the encryption keys, making it more difficult for attackers to crack. In the second round of encryption, the ciphertext is used as input into a hash function to generate a new key. Through a series of pixel-level operations, the security of the ciphertext is further enhanced. The algorithm is tested on a set of standard test images, and the information entropy of the ciphertext was found to be 7.9993, with correlations in the three directions being 0.0006, 0.0003, - 0.0012, respectively. Additionally, compared with existing image encryption algorithms, the results indicate that the image encryption algorithm based on the 2D-DDQCM and the feedback key mechanism provides an effective solution for the secure transmission of images. [ABSTRACT FROM AUTHOR]

In this study, we developed a residue number system (RNS), a numeral system consisting of an arbitrary number of pairwise coprime integers representing a specific integer by its value. We discovered that this system reduced the runtime or training speed of image processing. In addition, we observed that the characteristic operations of the core functions of the decentralized congruential system derived from the proposed system reduced the overall execution time or training speed of image processing. Both the speed of calculation and the properties of the congruential system ensured the accuracy and security of information after distributed processing. Overall, this approach enabled the use of different algorithms on microdevices while ensuring confidentiality. In summary, we developed a system capable of increasing the operation speed of image processing by 50% through core function precomputation, with a modified image data input, a modified core function, and a reverse core function. [ABSTRACT FROM AUTHOR]

Since the advent of networked systems, fuzzy graph theory has surfaced as a fertile paradigm for handling uncertainties and ambiguities. Among the different modes of handling challenges created by the uncertainties and ambiguities of current networked systems, integrating fuzzy graph theory with cryptography has emerged as the most promising approach. In this regard, this review paper elaborates on potentially studying fuzzy graph-based cryptographic techniques, application perspectives, and future research directions. Since the expressive power of fuzzy graphs allows the cryptographic schemes to handle imprecise information and to enhance security in many domains, several domains have benefited, such as image encryption, key management, and attribute-based encryption. The paper analyzes in depth the research landscape, mainly by focusing on the varied techniques used, such as fuzzy logic for key generation and fuzzy attribute representation for access control policies. A comparison with performance metrics unveils the trade-offs and advantages of different fuzzy graph-based approaches in efficiency, security strength, and computational overhead. Additionally, the survey explores the security applications of fuzzy graph-based cryptography and underpins potential development for secure communication in wireless sensor networks, privacy-preserving data mining, fine-grained access control in cloud computing, and blockchain security. Some challenges and research directions, such as the standardization of fuzzy logic operators, algorithmic optimization, integration with emerging technologies, and exploitation of post-quantum cryptography applications, are also brought out. This review will thus bring insight into this interdisciplinary domain and stimulate further research for the design of more robust, adaptive, and secure cryptographic systems in the wake of rising complexities and uncertainties. [ABSTRACT FROM AUTHOR]