Improved Secure Integer Comparison via Homomorphic Encryption

Secure integer comparison has been one of the first problems introduced in cryptography, both for its simplicity to describe and for its applications. The first formulation of the problem was to enable two parties to compare their inputs without revealing the exact value of those inputs, also called the Millionaires\u27 problem. The recent rise of fully homomorphic encryption has given a new formulation to this problem. In this new setting, one party blindly computes an encryption of the boolean $(a<b)$ given only ciphertexts encrypting $a$ and $b$. In this paper, we present new solutions for the problem of secure integer comparison in both of these settings. The underlying idea for both schemes is to avoid decomposing the integers in binary in order to improve the performances. Our fully homomorphic based solution is inspired by Bourse et al, and makes use of the fast bootstrapping techniques recently developpedto obtain scalability for large integers while preserving high efficiency. On the other hand, our solution to the original Millionaires\u27 problem is inspired by the protocol of Carlton et al, based on partially homomorphic encryption. We tweak their protocol in order to minimize the number of interactions required, while preserving the advantage of comparing non-binary integers. Both our techniques provide efficient solutions to the problem of secure integer comparison for large (even a-priori unbounded in our first scenario) integers with minimum interaction

Self-monitoring of the tympanic membrane: An opportunity for telemedicine during times of COVID-19 and beyond

The interest for telemedicine has increased since the COVID-19 pandemic because of the risk of infection. Recently, commercial companies started selling digital USB-otoscopes (DUO) that can be connected to a mobile phone. These DUOs are inexpensive (costing approximately $6–35 each) and make it possible to visualize the whole tympanic membrane. Here, we illustrate the case of a patient who had operative correction of a tympanic membrane retraction, and who self-monitored the tympanic membrane in the course of time. Additionally, we discuss the use of DUOs in otolaryngology telemedicine practice. The use of simple digital USB otoscopes provides a promising method to assess and monitor the tympanic membrane remotely. However, more research is needed to establish the role of DUOs in telemedicine

Corneal Transplantation for Infectious Keratitis:A Prospective Dutch Registry Study

PURPOSE: The aim of this study was to analyze real-world practice patterns and graft survival after corneal transplantation for infectious keratitis in the Netherlands. METHODS: All consecutive keratoplasties for infectious keratitis registered in the Netherlands Organ Transplant Registry were included. Graft survival was analyzed using Kaplan-Meier survival curves with Cox regression to compare the 3 most common pathogens with subgroup analysis for type and reason of transplantation, sex, and graft size. Multivariable analysis was performed using the same explanatory factors. RESULTS: Between 2007 and 2017, 1111 keratoplasties for infectious keratitis were registered in the Netherlands Organ Transplant Registry. The most common pathogens were viruses (n = 437), bacteria (n = 271), and Acanthamoeba (n = 121). Human leukocyte antigen (HLA) matching did not provide a significant survival benefit, whereas emergency procedures showed worse graft survival [hazard ratio (HR) = 0.40, P = 0.120; HR = 2.73, P &lt; 0.001, respectively]. Graft size &gt;8.5 mm was significantly worse than graft size 8.5 mm (HR = 2.062, P = 0.010). In therapeutic keratoplasty, graft survival was significantly worse for Acanthamoeba than viral keratitis (HR = 2.36, P = 0.008). In the multivariable model, adjusting for graft size, type, and reason for transplantation, viral and bacterial keratitis did not differ significantly in graft survival, and Acanthamoeba showed a significantly worse prognosis (vs. viral keratitis, HR = 2.30, P &lt; 0.001; bacterial keratitis, HR = 2.65, P &lt; 0.001). CONCLUSIONS: Viral keratitis was the most common indication for transplantation, followed by bacterial and Acanthamoeba keratitis. HLA matching did not offer protection over elective non-HLA-matched procedures, whereas emergency procedures and grafts sized &gt;8.5 mm showed poor survival. In optical keratoplasty, survival is high for all pathogens, whereas in therapeutic keratoplasty Acanthamoeba shows poor outcome

Enzymatic Digestion of Porcine Corneas Cross-linked by Hypo- and Hyperosmolar Formulations of Riboflavin/ultraviolet A or WST11/Near-Infrared Light

Purpose: To assess enzymatic digestion rate after Riboflavin (RF) and Water-Soluble-Taurine (WST11) based corneal cross-linking (CXL), with or without the addition of high molecular weight dextran (RF-D and WST-D). Methods: Eighty-eight paired porcine corneas were cross-linked by either RF (n = 11) or RF-D (n = 11) and ultraviolet light (UVA), or WST11 (n = 11) or WST-D (n = 11) and near-infrared (NIR) light, or used as paired control (n = 44). Corneal buttons of treated and paired control eyes were placed in a 0.3% collagenase solution. Time to full digestion and remaining dry sample weight after six hours were compared. Results: A strong treatment effect was seen with all four formulations, as all controls had been fully digested whilst all treated samples were still visible at the experiment’s endpoint. After irradiation, central corneal thickness was significantly higher in samples treated with hypo-osmolar formulations, compared to dextran enriched formulations (P < 0.001). Dry sample weight after digestion was nonsignificantly different between corneas treated by the four different formulations (P = 0.102). Average dry sample weight was 1.68 ± 0.6 (n = 10), 2.19 ± 0.50 (n = 8), 1.48 ± 0.76 (n = 11), and 1.54 ± 0.60 (n = 9) mg, for RF, RF-D, WST11, and WST-D treated samples, respectively. Enzymatic resistance was similar for RF and WST based CXL (P = 0.61) and was not affected by the addition of dextran (P = 0.221). Conclusions: Both RF and WST11 based CXL significantly increases resistance to enzymatic digestion, with similar effect for hypo-osmolar and hyperosmolar (dextran enriched) formulations. Translational Relevance: Our findings indicate these formulations are interchangeable, paving the way for the development of novel PACK-CXL protocols for thin corneas and deep-seated infections