Assessing the Privacy Benefits of Domain Name Encryption

As Internet users have become more savvy about the potential for their Internet communication to be observed, the use of network traffic encryption technologies (e.g., HTTPS/TLS) is on the rise. However, even when encryption is enabled, users leak information about the domains they visit via DNS queries and via the Server Name Indication (SNI) extension of TLS. Two recent proposals to ameliorate this issue are DNS over HTTPS/TLS (DoH/DoT) and Encrypted SNI (ESNI). In this paper we aim to assess the privacy benefits of these proposals by considering the relationship between hostnames and IP addresses, the latter of which are still exposed. We perform DNS queries from nine vantage points around the globe to characterize this relationship. We quantify the privacy gain offered by ESNI for different hosting and CDN providers using two different metrics, the k-anonymity degree due to co-hosting and the dynamics of IP address changes. We find that 20% of the domains studied will not gain any privacy benefit since they have a one-to-one mapping between their hostname and IP address. On the other hand, 30% will gain a significant privacy benefit with a k value greater than 100, since these domains are co-hosted with more than 100 other domains. Domains whose visitors' privacy will meaningfully improve are far less popular, while for popular domains the benefit is not significant. Analyzing the dynamics of IP addresses of long-lived domains, we find that only 7.7% of them change their hosting IP addresses on a daily basis. We conclude by discussing potential approaches for website owners and hosting/CDN providers for maximizing the privacy benefits of ESNI.Comment: In Proceedings of the 15th ACM Asia Conference on Computer and Communications Security (ASIA CCS '20), October 5-9, 2020, Taipei, Taiwa

Peri-procedural care of renal nerve ablation candidates

Percutaneous catheter-based transluminal renal nerve ablation (RNA) by delivery of radiofrequency energy constitutes a novel therapeutic strategy for the treatment of resistant hypertension. The sympathetic nervous activation to the kidney and the sensory afferent signals to the central nervous system represent the targets of RNA. In this review we summarize current recommendations for appropriate patient selection for RNA and multimodal strategies in order to optimize pharmacological treatment for resistant hypertension. The safety and efficacy of the RNA based on published trials are also presented. Furthermore, a detailed description of the periprocedural management, the methodology of the RNA procedure and appropriate follow-up are provided. In conclusion, in order to improve the overall clinical outcome and achieve optimal management of resistant hypertensive patients before and after the RNA, experienced and certified centers are of major importance. © 2013 Bentham Science Publishers

Soluble receptor for advanced glycation end-product levels are related to albuminuria and arterial stiffness in essential hypertension

Background and aims: Emerging evidence suggests that the soluble receptor for advanced glycation end-products (sRAGE) is implicated in the development of vascular disease. We investigated the interrelationships of sRAGE with albumin to creatinine ratio (ACR) and arterial stiffness in essential hypertension. Methods and results: In 309 untreated non-diabetic hypertensives, ACR values were determined as the mean of three non-consecutive morning spot urine samples and aortic stiffness was evaluated on the basis of carotid to femoral pulse wave velocity (c-f PWV). In all subjects, venous blood sampling was performed for the estimation of sRAGE levels. Patients with low (n = 155) compared to those with high sRAGE values (n = 154) had greater 24-h systolic BP (140 ± 8 vs. 134 ± 7 mmHg, p < 0.0001), exhibited higher ACR (36.3 ± 51.6 vs. 17.2 ± 1.2 mg g-1, p < 0.0001) and c-f PWV (8.3 ± 1.5 vs. 7.8 ± 1.1 m s-1, p = 0.003), independently of confounding factors. Multiple regression analyses revealed that age, male sex, 24-h systolic BP and sRAGE were the 'independent correlates' of ACR (R2 = 0.493, p < 0.0001), while age, 24-h systolic BP and sRAGE were the 'independent correlates' of c-f PWV (R2 = 0.428, p < 0.0001). Conclusion: In hypertensives, decreased sRAGE levels are accompanied by pronounced albuminuria and arterial stiffening. The association of sRAGE with ACR and c-f PWV suggests involvement of sRAGE in the progression of hypertensive vascular damage. © 2011 Elsevier B.V

Noninvasive assessment of haemodynamics in resistant hypertension: The role of the renal resistive index

Objective: The association of resistant hypertension (RHTN) with renal haemodynamics is unclear. Our aim was to evaluate differences in haemodynamic characteristics of patients with RHTN compared with patients with controlled hypertension (HTN) at the level of the heart, kidney and aorta. Methods: We studied 50 patients with RHTN confirmed by ambulatory blood pressure monitoring and 50 controlled hypertensive patients matched for age and sex. All participants underwent renal Doppler ultrasound to determine the renal resistive index (RRI), a complete echocardiographic study including measurements of diastolic function and evaluation of augmentation index. Results: Hypertensive patients with RHTN compared with those without RHTN had a significantly decreased E/A ratio (by 0.12, P=0.043), an increased E/e′ ratio (by 3.1, P < 0.001), increased albumin-to-creatinine ratio levels (by 49 mg/g, P=0.023) and a significantly higher RRI (by 0.078, P<0.001) but similar augmentation index values (P = 0.79). Logistic regression revealed that presence of RHTN was the strongest predictor of an RRI more than 0.7 after controlling for other haemodynamic variables including blood pressure levels. Receiver-operator characteristic analysis revealed an area under the curve for prediction of RHTN by the RRI alone of 80.3% (95% confidence interval: 0.72-0.89, P<0.001). An RRI cutpoint of 0.648 has a sensitivity of 78% and a specificity of 72% for prediction of RHTN. Conclusion: In a well treated hypertensive population, patients with RHTN show more pronounced renal and cardiac haemodynamic dysfunction compared with patients with controlled HTN. A greater RRI seems to be associated with RHTN and may help identify such patients. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved