12,928 research outputs found
Identity based proxy re-encryption scheme (IBPRE+) for secure cloud data sharing
(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.In proxy re-encryption (PRE), a proxy with re-encryption keys can transfer aciphertext computed under Alice's public key into a new one, which can be decrypted by Bob only with his secret key. Recently, Wang et al. introduced the concept of PRE plus (PRE+) scheme, which can be seen as the dual of PRE, and is almost the same as PRE scheme except that the re-encryption keys are generated by the encrypter. Compared to PRE, PRE+ scheme can easily achieve two important properties: first, the message-level based fine-grained delegation and, second, the non-transferable property. In this paper, we extend the concept of PRE+ to the identity based setting. We propose a concrete IBPRE+ scheme based on 3-linear map and roughly discuss its properties. We also demonstrate potential application of this new primitive to secure cloud data sharing.Peer ReviewedPostprint (author's final draft
Treatment of Linear and Nonlinear Dielectric Property of Molecular Monolayer and Submonolayer with Microscopic Dipole Lattice Model: I. Second Harmonic Generation and Sum-Frequency Generation
In the currently accepted models of the nonlinear optics, the nonlinear
radiation was treated as the result of an infinitesimally thin polarization
sheet layer, and a three layer model was generally employed. The direct
consequence of this approach is that an apriori dielectric constant, which
still does not have a clear definition, has to be assigned to this polarization
layer. Because the Second Harmonic Generation (SHG) and the Sum-Frequency
Generation vibrational Spectroscopy (SFG-VS) have been proven as the sensitive
probes for interfaces with the submonolayer coverage, the treatment based on
the more realistic discrete induced dipole model needs to be developed. Here we
show that following the molecular optics theory approach the SHG, as well as
the SFG-VS, radiation from the monolayer or submonolayer at an interface can be
rigorously treated as the radiation from an induced dipole lattice at the
interface. In this approach, the introduction of the polarization sheet is no
longer necessary. Therefore, the ambiguity of the unaccounted dielectric
constant of the polarization layer is no longer an issue. Moreover, the
anisotropic two dimensional microscopic local field factors can be explicitly
expressed with the linear polarizability tensors of the interfacial molecules.
Based on the planewise dipole sum rule in the molecular monolayer, crucial
experimental tests of this microscopic treatment with SHG and SFG-VS are
discussed. Many puzzles in the literature of surface SHG and SFG spectroscopy
studies can also be understood or resolved in this framework. This new
treatment may provide a solid basis for the quantitative analysis in the
surface SHG and SFG studies.Comment: 23 pages, 3 figure
Synapse: Trajectory-as-Exemplar Prompting with Memory for Computer Control
Building agents using large language models (LLMs) to control computers is an
emerging research field, where the agent perceives computer states and performs
actions to accomplish complex tasks. Previous computer agents have demonstrated
the benefits of in-context learning (ICL); however, their performance is
hindered by several issues. First, the limited context length of LLMs and
complex computer states restrict the number of exemplars, as a single webpage
can consume the entire context. Second, the exemplars in current methods, such
as high-level plans and multi-choice questions, cannot represent complete
trajectories, leading to suboptimal performance in tasks that require many
steps or repeated actions. Third, existing computer agents rely on
task-specific exemplars and overlook the similarity among tasks, resulting in
poor generalization to novel tasks. To address these challenges, we introduce
Synapse, featuring three key components: i) state abstraction, which filters
out task-irrelevant information from raw states, allowing more exemplars within
the limited context, ii) trajectory-as-exemplar prompting, which prompts the
LLM with complete trajectories of the abstracted states and actions for
improved multi-step decision-making, and iii) exemplar memory, which stores the
embeddings of exemplars and retrieves them via similarity search for
generalization to novel tasks. We evaluate Synapse on MiniWoB++, a standard
task suite, and Mind2Web, a real-world website benchmark. In MiniWoB++, Synapse
achieves a 99.2% average success rate (a 10% relative improvement) across 64
tasks using demonstrations from only 48 tasks. Notably, Synapse is the first
ICL method to solve the book-flight task in MiniWoB++. Synapse also exhibits a
53% relative improvement in average step success rate over the previous
state-of-the-art prompting scheme in Mind2Web.Comment: 22 pages, 7 figure
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