On the Security of RSA with Primes Sharing Least-Significant Bits

We investigate the security of a variant of the RSA public-key cryptosystem called LSBS-RSA, in which the modulus primes share a large number of least-significant bits. We show that low public-exponent LSBS-RSA is inherently resistant to Partial Key Exposure (PKE) attacks in which least-significant bits of the secret exponent are revealed to the attacker, and in particular that the Boneh-Durfee-Frankel PKE attack [5] on low public-exponent RSA is less effective for LSBS-RSA systems than for standard RSA. On the other hand, we show that large public-exponent LSBS-RSA is more vulnerable to such attacks than standard RSA. An application to server-aided RSA signature generation is proposed.This is an extended version of an earlier paper presented at the Cryptographers Track RSA Conference (CT-RSA 2001), April 8-12 2001, San Francisco, USA [20].This work was done while the author was at the School of Network Computing, Monash University, Frankston, Australia.Acknowledgement The authors would like to thank the anonymous referees of CT-RSA 2001 for their helpful comments on a preliminary version [20] of some of the results in this paper.     

Selecting exposure measures in crash rate prediction for two-lane highway segments

A critical part of any risk assessment is identifying how to represent exposure to the risk involved. Recent research shows that the relationship between crash count and traffic volume is non-linear; consequently, a simple crash rate computed as the ratio of crash count to volume is not proper for comparing the safety of sites with different traffic volumes. To solve this problem, we describe a new approach for relating traffic volume and crash incidence. Specifically, we disaggregate crashes into four types: (1) single-vehicle, (2) multi-vehicle same direction, (3) multi-vehicle opposite direction, and (4) multi-vehicle intersecting, and define candidate exposure measures for each that we hypothesize will be linear with respect to each crash type. This paper describes initial investigation using crash and physical characteristics data for highway segments in Michigan from the Highway Safety Information System (HSIS). We use zero-inflated-Poisson (ZIP) modeling to estimate models for predicting counts for each of the above crash types as a function of the daily volume, segment length, speed limit and roadway width. We found that the relationship between crashes and the daily volume (AADT) is non-linear and varies by crash type, and is significantly different from the relationship between crashes and segment length for all crash types. Our research will provide information to improve accuracy of crash predictions and, thus, facilitate more meaningful comparison of the safety record of seemingly similar highway locations.     

Does increased confidence among novice drivers imply a decrease in safety? The effects of skid training on slippery road accidents

Finnish driver training was renewed in 1990 with the inclusion of a compulsory skid training course in the curriculum. The study evaluated the renewal's effect on accidents in slippery road conditions. A questionnaire was sent by mail to 41000 novice drivers who were randomly selected from the official register of driving licences. It included questions on driving exposure and the accidents the drivers had been involved in during 6-18 months following licensing. The rate of return was 74.7%. Half of the drivers had received their licence in 1989 and had, therefore, not received any skid training. The other half had received their licence in 1990 after the introduction of the skid training course. The results showed no effects of the renewal on slippery road accidents for either male or female drivers. Another questionnaire was sent to 1300 old and new curriculum drivers immediately after licensing and a second time 1/2-1 year later, both with questions about skills, worries and perceived risks regarding driving in slippery conditions. The new curriculum drivers showed higher confidence in their skills and they were less afraid to drive in slippery conditions than the old curriculum drivers. This increase in confidence as a result of skid training is discussed. It is argued that high confidence in one's personal skills does not necessarily imply negative safety. The crucial factor is how these skills are used, and for what purpose.     

Characterization and variability of endotoxin and 3-hydroxy fatty acids in an office building during a particle intervention study

Air and dust samples were collected on two floors of an office building during a double-blind particle intervention study to examine spatial and temporal variability of airborne endotoxin over a period of weeks, and to characterize endotoxin activity and lipopolysaccharide (LPS) content in carpet and chair dust. Air samples were collected on multiple days within and across weeks. Dust samples were collected from carpets and chairs one day per week for three weeks. Endotoxin was measured using a Limulus assay. Dust samples were analyzed for LPS by determination of 3-hydroxy fatty acids (3-OHFAs) using gas chromatography-mass spectrometry. The geometric mean (geometric standard deviation) for 96 indoor air samples was 0.24 (1.6) EU/m3. Significant within-floor spatial variation of airborne endotoxin was found (P < 0.0001, n = 80). Temporal variability of airborne endotoxin was not significant across weeks. Mean (+/- SD) endotoxin levels in carpet dust (59 +/- 9.3 EU/mg dust, n = 12) and in chair dust (38 +/- 7.7 EU/mg dust, n = 10) were significantly different (P < 0.001). Carbon chain length-dependent differences in 3-OHFA levels by dust source and floor were found. Enhanced air filtration did not significantly affect airborne endotoxin (P = 0.62); however, total dust mass and total endotoxin in carpet dust samples increased significantly after enhanced surface cleaning (P < 0.01). These findings suggest that spatial variability, dust source, and surface cleaning may influence building occupant exposures to endotoxin.     

Indoor air quality in Michigan schools

Indoor air quality (IAQ) parameters in 64 elementary and middle school classrooms in Michigan were examined for the purposes of assessing ventilation rates, levels of volatile organic compounds (VOCs) and bioaerosols, air quality differences within and between schools, and emission sources. In each classroom, bioaerosols, VOCs, CO(2), relative humidity, and temperature were monitored over one workweek, and a comprehensive walkthough survey was completed. Ventilation rates were derived from CO(2) and occupancy data. Ventilation was poor in many of the tested classrooms, e.g., CO(2) concentrations often exceeded 1000 ppm and sometimes 3000 ppm. Most VOCs had low concentrations (mean of individual species <4.5 microg/m(3)); bioaerosol concentrations were moderate (<6500 count per m(3) indoors, <41,000 count per m(3) outdoors). The variability of CO(2), VOC, and bioaerosol concentrations within schools exceeded the variability between schools. These findings suggest that none of the sampled rooms were contaminated and that no building-wide contamination sources were present. However, localized IAQ problems might remain in spaces where contaminant sources are concentrated and that are poorly ventilated. PRACTICAL IMPLICATIONS: Indoor air quality (IAQ) is a continuing concern for students, parents, teachers, and school staff, leading to many complaints regarding poor IAQ. Investigations of these complaints often include air sampling, which must be carefully conducted if representative data are to be collected. To better understand sampling results, investigators need to account for the variability of contaminants both within and between schools.     

钴—60远距离治疗源的活度

本文简述了钴-60远距离治疗源的照射量率测量、活度计算及其误差分析。结果的合成不确定度分别小于±4%和±10%。同时,它适用于其它高活度钴-60密封源.     

对公众慢性照射防护的一些讨论

本文介绍了近年来国际放射防护委员会（ＩＣＲＰ）、国际原子能机构（ＩＡＥＡ）以及一些学者对公众慢性照射防护问题的一些讨论,涉及定义与范围、相关量、ＩＣＲＰ防护体系的应用以及实用指南等。它可以作为制订我国《电离辐射防护和辐射源安全的基本安全标准》的借鉴。     

广东省部分陶瓷产品的放射性水平

对广东省主要陶瓷产地(南海、佛山和潮州三市)的陶瓷产品中的天然放射性水平进行抽样检测，结果表明：所检测154个样品中95％的样品放射性含量指标符合国家标准GB6566-2001《建筑材料放射性核素限量》规定的A类产品标准。     

Metabolic and DNA Repair Variations in Susceptibility to Genotoxins

An overview on the influence of metabolic and DNA repair polymorphisms on biological indicators of genotoxic risk in occupational, environmental, or lifestyle exposure is presented in this article. Indicators of genotoxic risk include biomarkers of internal dose (urinary concentration of the substance or its metabolites and urinary mutagenicity), biological effective dose (protein and DNA adducts), and indicators of early biological effects (chromosome aberrations, sister chromatid exchanges, micronuclei, COMET assay, HPRT mutants). Genetic polymorphisms include those involved in the activation and detoxification (i.e., P-450 cytochrome, acetyltransferase, glutathione transferase) of various classes of carcinogens and the newly discovered polymorphisms affecting DNA repair enzymes. Genetic polymorphisms are assessed for their importance in detecting the impact of genotype on biological indicators of genotoxic risk.     

实际应用推动辐射防护体系的不断完善

本文在简要回顾国际放射防护委员会（ＩＣＲＰ）历史的基础上，首先指出在伴随着核辐射和核能的应用不断发展的同时，由ＩＣＲＰ基本建议书推荐的辐射防护体系也在实际应用中不断完善和改进。接着简要介绍了目前倍受关心的两个实际问题及其有关初步建议。文中再次强调了ＩＣＲＰ的几个重要基本观点，以及与此相悖的“打擦边球”和“零危险”两种偏面看法。最后指出，我们应该在借鉴国际经验的同时，认真总结自己的经验，为全世界共同的辐射防护事业作出我们应有的贡献。