Elliptisten käyrien kryptografia

Kryptografia, eli tiedon salaus, on nopeasti kehittyvä ala, joka on läsnä ihmisten päivittäisessä toiminnassa. Perinteisen tiedon salauksen lisäksi kryptografian avulla voidaan toteuttaa monipuolisia toiminnallisuuksia, kuten digitaaliset allekirjoitukset ja avaimenvaihto. Nämä toiminnallisuudet on mahdollista toteuttaa julkisen avaimen kryptografian avulla. Elliptiset käyrät ovat kuutiollisia tasokäyriä, joiden pisteiden välille voidaan määritellä yhteenlaskuoperaatio. Näin ollen elliptisen käyrän pisteet muodostavat Abelin ryhmän, joten niitä on mahdollista käyttää diskreetin logaritmin ongelmaan perustuvissa kryptosysteemeissä, eli julkisen avaimen kryptosysteemeissä. Elliptisten käyrien kryptografisten algoritmien suojaustaso perustuu elliptisen käyrän diskreetin logaritmin ongelmaan, jonka yleiselle muodolle ei olla löydetty subeksponentiaalista ratkaisua. Näin ollen elliptisten käyrien kryptografialla on mahdollista saavuttaa vastaava suojaustaso lyhyemmillä avaimilla, verrattuna muihin julkisen avaimen kryptografian metodeihin. Tutkielman ensimmäisessä osassa perehdytään elliptisten käyrien teoriaan keskittyen tärkeimpiin teemoihin kryptografian kannalta. Luvussa esitetään yhteenlasku elliptisen käyrän pisteille ja johdetaan ryhmälait. Erityisesti käsitellään kryptografiassa käytettäviä äärellisissä kunnissa määriteltyjä elliptisiä käyriä, joita on kaksi yleisintä luokkaa: alkulukukunnissa ja binäärikunnissa määritellyt käyrät. Tutkielman toisen osan keskiössä on kryptografia; julkisen avaimen kryptografia ja erityisesti elliptisen käyrän kryptografia ovat keskiössä. Luvussa tarkastellaan elliptisen käyrän diskreetin logaritmin ongelmaa ja elliptisen käyrän rakenteeseen liittyviä tuloksia. Tutkielman lopussa esitetään algoritmit kullekin julkisen avaimen kryptografian avulla toteutettavalle toiminnallisuudelle käyttäen elliptisten käyrien kryptografian algoritmeja. Avaimenvaihdosta käytetään esimerkkinä elliptisen käyrän Diffie-Hellman avaimenvaihtoa ja digitaalisesta allekirjoituksesta elliptisen käyrän digitaalista allekirjoitusalgoritmia. Salaus ja purku menetelmänä esitellään elliptisen käyrän integroitu salaus -skeema

Season of birth affects the risk of adult-onset asthma in Finland

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Age- and gender-specific incidence of new asthma diagnosis from childhood to late adulthood

Background: Asthma is currently divided into different phenotypes, with age at onset as a relevant differentiating factor. In addition, asthma with onset in adulthood seems to have a poorer prognosis, but studies investigating age-specific incidence of asthma with a wide age span are scarce. Objective: To evaluate incidence of asthma diagnosis at different ages and differences between child- and adult-diagnosed asthma in a large population-based study, with gender-specific analyzes included. Methods: In 2016, a respiratory questionnaire was sent to 8000 randomly selected subjects aged 20-69 years in western Finland. After two reminders, 4173 (52.3%) subjects responded. Incidence rate of asthma was retrospectively estimated based on the reported age of asthma onset. Adult-diagnosed asthma was defined as a physician-diagnosis of asthma made at >= 18 years of age. Results: Among those with physician-diagnosed asthma, altogether, 63.7% of subjects, 58.4% of men and 67.8% of women, reported adult-diagnosed asthma. Incidence of asthma diagnosis was calculated in 10-year age groups and it peaked in young boys (0-9 years) and middle-aged women (40-49 years) and the average incidence rate during the examined period between 1946 and 2015 was 2.2/1000/year. Adult-diagnosed asthma became the dominant phenotype among those with physician-diagnosed asthma by age of 50 years and 38 years in men and women, respectively. Conclusions: Asthma is mainly diagnosed during adulthood and the incidence of asthma diagnosis peaks in middle-aged women. Asthma diagnosed in adulthood should be considered more in clinical practice and management guidelines.Peer reviewe

Asthma Remission by Age at Diagnosis and Gender in a Population-Based Study

BACKGROUND: Child-onset asthma is known to remit with high probability, but remission in adult-onset asthma is seem-ingly less frequent. Reports of the association between remission and asthma age of onset up to late adulthood are scarce. OBJECTIVE: To evaluate the association between asthma remission, age at diagnosis and gender, and assess risk factors of nonremission. METHODS: In 2016, a random sample of 16,000 subjects aged 20 to 69 years from Helsinki and Western Finland were sent a FinEsS questionnaire. Physician-diagnosed asthma was catego-rized by age at diagnosis to early-(0-11 years), intermediate-(12-39 years), and late-diagnosed (40-69 years) asthma. Asthma remission was defined by not having had asthma symptoms and not having used asthma medication in the past 12 months. RESULTS: Totally, 8199 (51.5%) responded, and 879 reported physician-diagnosed asthma. Remission was most common in early-diagnosed (30.2%), followed by intermediate-diagnosed (17.9%), and least common in late-diagnosed asthma (5.0%) (P < .001), and the median times from diagnosis were 27, 18.5, and 10 years, respectively. In males, the corresponding remission rates were 36.7%, 20.0%, and 3.4%, and in females, 20.4%, 16.6%, and 5.9% (gender difference P < .001). In multivariable binary logistic regression analysis, signifi-cant risk factors of asthma nonremission were intermediate (odds ratio [OR] = 2.15, 95% confidence interval: 1.373.36) and late diagnosis (OR = 11.06, 4.82-25.37) compared with early diagnosis, chronic obstructive pulmonary disease (COPD) (OR = 5.56, 1.26-24.49), allergic rhinitis (OR = 2.28, 1.50-3.46), and family history of asthma (OR = 1.86, 1.22-2.85). Results were similar after excluding COPD. CONCLUSION: Remission was rare in adults diagnosed with asthma after age 40 years in both genders. Late-diagnosed asthma was the most significant independent risk factor for nonremission. (C) 2020 American Academy of Allergy, Asthma & ImmunologyPeer reviewe

Cluster Analysis of Finnish Population-Based Adult-Onset Asthma Patients

Background: Phenotypes of adult asthma have been identified in previous studies but rarely in population-based settings. Objective: To identify clusters of adult-onset asthma in a Finnish population-based study on subjects born before 1967. Methods: We used population-based data from 1350 asthmatics with adult-onset asthma (Adult Asthma in Finland) from Finnish national registers. Twenty-eight covariates were selected based on literature. The number of covariates was reduced by using factor analysis before cluster analysis. Results: Five clusters (CLU1-CLU5) were identified, 3 clusters with late-onset adult asthma (onset ≥40 years) and 2 clusters with onset at earlier adulthood (<40 years). Subjects in CLU1 (n = 666) had late-onset asthma and were nonobese, symptomatic, and predominantly female with few respiratory infections during childhood. CLU2 (n = 36) consisted of subjects who had earlier-onset asthma, were predominantly female, obese with allergic asthma, and had recurrent respiratory infections. Subjects in CLU3 (n = 75) were nonobese, older, and predominantly men with late-onset asthma, smoking history, comorbidities, severe asthma, least allergic diseases, low education, many siblings, and childhood in rural areas. CLU4 (n = 218) was a late-onset cluster consisting of obese females with comorbidities, asthma symptoms, and low education level. Subjects in CLU5 (n = 260) had earlier onset asthma, were nonobese, and predominantly allergic females. Conclusions: Our population-based adult-onset asthma clusters take into account several critical factors such as obesity and smoking, and identified clusters that partially overlap with clusters identified in clinical settings. Results give us a more profound understanding of adult-onset asthma phenotypes and support personalized management.publishedVersionPeer reviewe

Season of birth affects the risk of adult-onset asthma in Finland

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Season of birth affects the risk of adult-onset asthma in Finland

publishedVersionNon peer reviewe

Nonrespiratory Diseases in Adults Without and With Asthma by Age at Asthma Diagnosis

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