Topic
Scrambling
About: Scrambling is a research topic. Over the lifetime, 4507 publications have been published within this topic receiving 50786 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the authors study chaos and scrambling in unitary channels by considering their entanglement properties as states and propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling.
Abstract: We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.
649 citations
TL;DR: A bit-level permutation and high-dimension chaotic map to encrypt color image and security analysis show that the scheme can achieve good encryption result, but also that the key space is large enough to resist against common attack.
503 citations
TL;DR: In this paper, a lower bound on the scrambling time of systems with finite norm terms in their Hamiltonian was shown. But this lower bound holds in spite of any non-local structure in the Hamiltonian, which might permit every degree of freedom to interact directly with every other one.
Abstract: Many proposed quantum mechanical models of black holes include highly non-local interactions. The time required for thermalization to occur in such models should reflect the relaxation times associated with classical black holes in general relativity. Moreover, the time required for a particularly strong form of thermalization to occur, sometimes known as scrambling, determines the time scale on which black holes should start to release information. It has been conjectured that black holes scramble in a time logarithmic in their entropy, and that no system in nature can scramble faster. In this article, we address the conjecture from two directions. First, we exhibit two examples of systems that do indeed scramble in logarithmic time: Brownian quantum circuits and the antiferromagnetic Ising model on a sparse random graph. Unfortunately, both fail to be truly ideal fast scramblers for reasons we discuss. Second, we use Lieb-Robinson techniques to prove a logarithmic lower bound on the scrambling time of systems with finite norm terms in their Hamiltonian. The bound holds in spite of any nonlocal structure in the Hamiltonian, which might permit every degree of freedom to interact directly with every other one.
446 citations
TL;DR: In this article, the authors examined the nature of scrambling in Japanese in the light of Webelhuth (1989) and Mahajan (1989), and argued that these two apparently inconsistent hypotheses are both necessary for the analysis of scrambling.
Abstract: This paper examines the nature of scrambling in Japanese in the light of Webelhuth (1989) and Mahajan (1989). Webelhuth proposes that scrambling is uniformly movement to a third type of position, the non-operation/non-A position, and that this position has the binding properties of both A and A′ (operator) positions. Mahajan does not recognize the third type of position, and argues that clause-internal scrambling can be either A or A′ movement, while “long distance” scrambling is necessarily A′ movement. I argue in this paper that these two apparently inconsistent hypotheses are both necessary for the analysis of scrambling in Japanese. As evidence for Webelhuth's hypothesis, I show that unlike wh-movement, scrambling need not establish a semantically significant operator-variable relation. Then, I argue that Mahajan's hypothesis, based on the A/A′ dichotomy, is also needed to account for the distinction between clause-internal scrambling and “long distance” scrambling with respect to anaphor binding. Finally, adopting Tada's (1990) proposal that non-operator/non-A positions are licensed at S-structure but not at LF, I suggest that a modified version of Webelhuth's hypothesis applies at S-structure, and Mahajan's hypothesis applies at LF.
436 citations
TL;DR: A joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors is presented.
Abstract: Multimedia data security is very important for multimedia commerce on the Internet such as video-on-demand and real-time video multicast. Traditional cryptographic algorithms/systems for data security are often not fast enough to process the vast amount of data generated by multimedia applications to meet real-time constraints. This paper presents a joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors. The new approach is very simple to implement, yet provides considerable levels of security and different levels of transparency, and has a very limited adverse impact on compression efficiency and no adverse impact on error resiliency. Furthermore, it allows transcodability/scalability, and other content processing functionalities without having to access the cryptographic key and perform decryption and re-encryption.
375 citations