Blockchain Papers

S M Mostaq Hossain, Amani Altarawneh

No abstract is available for this record.

Jake Hecla, Areg Danagoulian

Nuclear disarmament treaties are not sufficient in and of themselves to neutralize the existential threat of the nuclear weapons. Technologies are necessary for verifying the authenticity of the nuclear warheads undergoing dismantlement before counting them towards a treaty partner's obligation. This work presents a novel concept that leverages isotope-specific nuclear resonance phenomena to authenticate a warhead's fissile components by comparing them to a previously authenticated template. All information is encrypted in the physical domain in a manner that amounts to a physical zero-knowledge proof system. Using Monte Carlo simulations, the system is shown to reveal no isotopic or geometric information about the weapon, while readily detecting hoaxing attempts. This nuclear technique can dramatically increase the reach and trustworthiness of future nuclear disarmament treaties.

Alex Glaser, Boaz Barak, Rob Goldston

Warhead verification systems proposed to date fundamentally rely on the use of information barriers to prevent the release of sensitive information. Measurements with information barriers significantly increase the complexity of inspection systems, make their certification and authentication difficult, and may reduce the overall confidence in the verifiability of future arms-control agreements. This article presents a concept for a new approach to nuclear warhead verification that minimizes the role of information barriers from the outset and envisions instead an inspection system that avoids the measurement of sensitive information, using a so-called zero-knowledge protocol. This is a protocol in which the data learned by one party (i.e., the inspector) allow him/her to verify that a statement is true (e.g., the inspected warhead is identical to an authenticated template), but does not reveal any additional information, e.g., does not leak any information that would help infer the design of the inspected warhead. There is a wide literature on zero knowledge proofs in the digital domain using cryptographic tools, and we draw on these ideas to achieve this in the physical domain. The proposed inspection system relies on active interrogation of a test object with 14-MeV neutrons, including both tomographic transmission measurements that are sensitive to warhead configuration, and scattering/fission measurements that are sensitive to material properties. The viability of the method is examined with MCNP Monte Carlo neutron transport calculations modeling the experimental setup.

Tsutomu Zeniya, Yoshiyuki Hirano, Tomonori Sakimoto, Kentaro Ishida · 10 authors

We designed a concept of high resolution and quantitative SPECT for imaging a selected small region-of-interest (ROI) of human brain. This system is aimed at achieving high resolution less than 1 mm and being applied for imaging neurons and evaluating drug delivery system. Pinhole or cone-beam collimators are useful for high-resolution imaging of small ROI. However, when the ROI is smaller than the object, the projection data are truncated by radioisotope outside ROI. In the reconstructed image, the truncation causes the artifact and the overestimation of voxel value, which deceases quantitative accuracy of physiological functions. We are introducing the new truncation compensated 3D-OSEM (TC-3DOSEM) reconstruction method. The truncated data can be successfully reconstructed within ROI by fulfilling the condition that ROI contains a priori knowledge. In addition to small field-of-view (FOV) detector, we are introducing the parallel-hole collimator attached large FOV detector covering the entire brain, to acquire the non-truncated data and provide the priori knowledge in small ROI, even if the resolution of the detector is low. For imaging with high resolution, we are using LaBr3(Ce) scintillator with optically coupled to position-sensitive photomultiplier tube (H8500, Hamamatsu, Japan) as the detector. And also, for proof of our concept, we performed preliminary experiment using pinhole SPECT and brain phantom. The reconstruction ROI contained the region outside the brain, that is, zero count as the priori knowledge. The truncated data were reconstructed by TC-3DOSEM. The reconstructed image without artifact and overestimation was obtained with high resolution. This preliminary experiment suggested feasibility of high resolution and quantitative SPECT for imaging a selected small ROI of human brain.