scholarly journals HMQV: A High-Performance Secure Diffie-Hellman Protocol

2005 ◽  
pp. 546-566 ◽  
Author(s):  
Hugo Krawczyk
Keyword(s):  
High Performance ◽  
Diffie Hellman

scholarly journals High-Performance RNS Modular Exponentiation by Sum-Residue Reduction

2020 ◽  
Author(s):  
Tao Wu
Keyword(s):  
High Performance ◽  
Computer Arithmetic ◽  
Number System ◽  
Residue Number System ◽  
Modular Exponentiation ◽  
Number Systems ◽  
Diffie Hellman ◽  
Residue Number ◽  
Diffie Hellman Key Exchange ◽  
Rsa Cryptography

Abstract Modular exponentiation is fundamental in computer arithmetic and is widely applied in cryptography such as ElGamal cryptography, Diffie-Hellman key exchange protocol, and RSA cryptography. Implementation of modular exponentiation in residue number system leads to high parallelism in computation, and has been applied in many hardware architectures. While most RNS based architectures utilizes RNS Montgomery algorithm with two residue number systems, the recent modular multiplication algorithm with sum-residues performs modular reduction in only one residue number system with about the same parallelism. In this work, it is shown that high-performance modular exponentiation and RSA cryptography can be implemented in RNS. Both the algorithm and architecture are improved to achieve high performance with extra area overheads, where a 1024-bit modular exponentiation can be completed in 0.567 ms in Xilinx XC6VLX195t-3 platform, costing 26,489 slices, 87,357 LUTs, 363 dedicated multipilers of $18\times 18$ bits, and 65 Block RAMs.

scholarly journals Password-authenticated searchable encryption

2020 ◽  
Author(s):  
Liqun Chen ◽  
Kaibin Huang ◽  
Mark Manulis ◽  
Venkkatesh Sekar
Keyword(s):  
Web Application ◽  
High Performance ◽  
Keyword Search ◽  
Searchable Encryption ◽  
Security Requirements ◽  
Single Server ◽  
Direct Construction ◽  
High Entropy ◽  
Legitimate User ◽  
Diffie Hellman

AbstractWe introduce Password Authenticated Searchable Encryption (PASE), a novel searchable encryption scheme where a single human-memorizable password can be used to outsource (encrypted) data with associated keywords to a group of servers and later retrieve this data through the encrypted keyword search procedure. PASE ensures that only the legitimate user who knows the initially registered password can perform these operations. In particular, PASE guarantees that no single server can mount an offline attack on the user’s password or learn any information about the encrypted keywords. The concept behind PASE protocols extends previous concepts behind searchable encryption by removing the requirement on the client to store high-entropy keys, thus making the protocol device-agnostic on the user side. In this paper, we model the functionality of PASE along with two security requirements (indistinguishability against chosen keyword attacks and authentication) and propose an efficient direct construction in a two-server setting those security we prove in the standard model under the Decisional Diffie–Hellman assumption. Our constructions support outsourcing and retrieval procedures based on multiple keywords and allow users to change their passwords without any need for the re-encryption of the outsourced data. Our theoretical efficiency comparisons and experimental performance and scalability measurements show that the proposed scheme is practical and offers high performance in relation to computations and communications on the user side. The practicality of our PASE scheme is further demonstrated through its implementation within a JavaScript-based web application that can readily be executed on any (mobile) browser and remains practical for commodity user devices such as laptops and smartphones.

scholarly journals SIDH on ARM: Faster Modular Multiplications for Faster Post-Quantum Supersingular Isogeny Key Exchange

2018 ◽  
pp. 1-20 ◽  
Author(s):  
Hwajeong Seo ◽  
Zhe Liu ◽  
Patrick Longa ◽  
Zhi Hu
Keyword(s):  
High Speed ◽  
High Performance ◽  
Key Exchange ◽  
Modular Arithmetic ◽  
Diffie Hellman ◽  
Real World Applications ◽  
Diffie Hellman Key Exchange ◽  
Memory Accesses ◽  
Montgomery Reduction ◽  
Cache Attacks

We present high-speed implementations of the post-quantum supersingular isogeny Diffie-Hellman key exchange (SIDH) and the supersingular isogeny key encapsulation (SIKE) protocols for 32-bit ARMv7-A processors with NEON support. The high performance of our implementations is mainly due to carefully optimized multiprecision and modular arithmetic that finely integrates both ARM and NEON instructions in order to reduce the number of pipeline stalls and memory accesses, and a new Montgomery reduction technique that combines the use of the UMAAL instruction with a variant of the hybrid-scanning approach. In addition, we present efficient implementations of SIDH and SIKE for 64-bit ARMv8-A processors, based on a high-speed Montgomery multiplication that leverages the power of 64-bit instructions. Our experimental results consolidate the practicality of supersingular isogeny-based protocols for many real-world applications. For example, a full key-exchange execution of SIDHp503 is performed in about 176 million cycles on an ARM Cortex-A15 from the ARMv7-A family (i.e., 88 milliseconds @2.0GHz). On an ARM Cortex-A72 from the ARMv8-A family, the same operation can be carried out in about 90 million cycles (i.e., 45 milliseconds @1.992GHz). All our software is protected against timing and cache attacks. The techniques for modular multiplication presented in this work have broad applications to other cryptographic schemes.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

Prospects for convergent beam electron diffraction with a 200kV cold field-emission transmission electron microscope

1991 ◽  
Vol 49 ◽  
pp. 466-467
Author(s):  
J W Steeds ◽  
R Vincent
Keyword(s):  
Field Emission ◽  
High Performance ◽  
Small Diameter ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Special Modification ◽  
Convergent Beam

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.

Current State of Biological High-Resolution Scanning Electron Microscopy

1988 ◽  
Vol 46 ◽  
pp. 180-181 ◽  
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Performance ◽  
Low Voltage ◽  
Backscattered Electrons ◽  
Lens Position ◽  
Low Voltage Operation ◽  
Signal Collection ◽  
Probe Size ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

A new generation of high performance field emission scanning electron microscopes (FSEM) is now commercially available (JEOL 890, Hitachi S 900, ISI OS 130-F) characterized by an "in lens" position of the specimen where probe diameters are reduced and signal collection improved. Additionally, low voltage operation is extended to 1 kV. Compared to the first generation of FSEM (JE0L JSM 30, Hitachi S 800), which utilized a specimen position below the final lens, specimen size had to be reduced but useful magnification could be impressively increased in both low (1-4 kV) and high (5-40 kV) voltage operation, i.e. from 50,000 to 200,000 and 250,000 to 1,000,000 x respectively.At high accelerating voltage and magnification, contrasts on biological specimens are well characterized1 and are produced by the entering probe electrons in the outmost surface layer within -vl nm depth. Backscattered electrons produce only a background signal. Under these conditions (FIG. 1) image quality is similar to conventional TEM (FIG. 2) and only limited at magnifications >1,000,000 x by probe size (0.5 nm) or non-localization effects (%0.5 nm).

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Improved 3-D reconstruction using stereo computer graphics and multiple tilt EM images

1995 ◽  
Vol 53 ◽  
pp. 630-631
Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang
Keyword(s):  
Computer Graphics ◽  
High Performance ◽  
Transverse Section ◽  
Three Dimensional ◽  
Stereo Pair ◽  
3D Reconstructions ◽  
Video Cameras ◽  
Biological Objects ◽  
Microscope Images ◽  
High Performance Computer

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.

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