Final Conclusions Memo Essay Example | Topics and Well Written Essays - 250 words

Final Conclusions Memo - Essay Example Louis which has won many games than the Boston and the difference in salary, is quite notable. Another variable is the attendance of the games. It is an expectation on everyone’s mind that the larger the attendances n the games the higher the players get paid. This is not the case, however, looking at the San Diego attendance as compared to the Boston, it was slightly higher, but the difference in the incomes is so higher. Boston earns a whopping 123.5$ San Diego earns 63.3$, while Chicago a team that earns a salary of 87.0$ with an attendance of more 3,100,092 million. This does not reflect in any way on the wins nor is the salary paid to the players. When it comes to baseball teams, it is exceptionally clear that money cannot make a team into a winning team. What actually makes a team to win is all about the player’s personality and the team chemistry not all about the salary they receive. A strong team requires a player with the same goals and the same

Patient Protection and Affordable Care Act Research Paper

Patient Protection and Affordable Care Act - Research Paper Example Patient Protection and Affordable Care Act, 2010 will go down in history as a major health care reform bill that has been signed into law. It has a comprehensive coverage that would see 31 million Americans currently uninsured getting a medical cover. If this new proposal, the government will incur approximately $848 billion over the next 10 years, consequently, there will be a gradual increase in taxes and revenue is proposed to reduce the total cost of this cover by $131 billion within the same period (Eaton 2010). The proposed reform aims at achieving a number of strategic healthcare goals. Firstly, it aims at ensuring that every US citizen can access, quality and affordable health care. In essence, this is an important component of the entire reform agenda. In light of the increasing burden of increasing burden of disease and skyrocketing prices of health care services, the government undertook this deliberate strategy to ensure that there is universal health care insurance cover age. Today, the majority of US citizens continues to battle with out-of-pocket financing, which is prohibitively expensive (Junior 2010). Secondly, it aims at improving quality and efficiency of healthcare by establishing a vibrant health care workforce that would meet the growing demand for healthcare services. In addition, there is a growing body of evidence showing an increase in the burden of chronic diseases, this proposed health care financing in its full implementation will see the middle and elderly persons receive a comprehensive cover that focuses on affordable health care services for chronic diseases. United States (2010) states that the Congressional Budget Office (CBO) has determined that the fully paid patient protection  scheme, in the end, will ensure that more than 94% of Americans will be covered within $900 billion limits set by President Obama.  

War and Peace international relations since 1914 Essay

War and Peace international relations since 1914 - Essay Example It was done so on 23rd July. The last part of July saw attack of Austria over Serbia. 28th July marked the day when Austria unleashed on Serbia. 31st July marked Germany’s attack on Russia on Eastern front. 3rd August marked attack of Germany on France. 4th August marked attack of Great Britain on Germany. Between 15th to 18th August, three major events took place. Russia took over parts of Prussia, and U.S.A reaffirmed its neutrality (Tuchman). The issues that came forth around the second and later stage of W.W.2 were pertinent to the post war settlements, say and influence and sharing of the spoils of war. Great Britain and U.S.A had soft corner for one another, Russia on other hand wanted maximum shares. It claimed those shares on account of the sacrifices and number of troops and other civilian casualties suffered by Russia. The case of Poland was another area of interest between these two. Russia wanted major say and influence in the affairs of European countries that had been unseated, while United States of America wanted to break the shackles and come out of the old custom of isolation. Great Britain on other side wanted to maintain its influence and presence through economic strengthening and importance of seas. The case of Germany and the influence maintaining was another area of conflict that came up in the later part of the Second World War (Keylor, 85). Iron Curtain was an important speech that is still remembe red as a hall mark of those days. The conflict gave rise to Cold war which lasted for over five decades after the end of Second World War. The relationship between these two groups had fragmented the continent of Europe into two distinct blocs. Both were drawn by the spirit of hatred, ill will, suspicion towards one another. Each aimed at outsmarting one another through military might and counter maneuvers. The Triple Entente was driven by historic relationship and strong ties. The central powers had come together

Financial Planning Essay Example | Topics and Well Written Essays - 2000 words - 1

Financial Planning - Essay Example The role of three companies, like Colonial First State Investments Limited and Professional Investment Services Pty Ltd related to provide financial planning services has been sorted out in the assigned study. The of Financial planning in Australia begun in the years 80s, as during those years there were no Financial Planners as they were not existing then. This occurred due to the fact that as there was no prerequisites for the clients within the Marketplace to enable them get efficient financial advice. It was only network of insurance that existed during that period under review. The Financial Planning Association of Australia (FPA) is the peak professional body for Australia's financial planners, representing approximately 12,000 individuals and businesses (The Financial Planning Association of Australia (FPA). However, (Cowen, Blair, Taylor, 2006, p 4) reveals that "In the early 1980s, a leading Australian financial planning industry stalwart Gwen Fletcher visited the United States intent on pursuing discussions with the U.S. industry association, the International Association for Financial Planning (IAFP). These discussions related to the creation of either a new industry body for A ustralia or the establishment of an affiliated chapter of the IAFP. At a later meeting of dealers conducted by the Department of Corporate Affairs (the then-regulatory body issuing licenses to dealers of securities), the affiliation model was proposed but rejected. However, a new industry body consisting of an elite group of independent advisors was formed, the Association of Independent Professional Advisors (AIPA). It is important to note that this group excluded all banks and insurance companies from membership". Additionally, following the International Conference of IAFP held in Australia in the years 1982 and 1984 respectively, Australian IAFP was officially launched. (Cowen, Blair, Taylor, 2006, p 4) states that after the launching, "The IAFP in Australia was to be an open forum for individuals, dealers and fund managers alike. Following U.S. IAFP requirements, the newly formed Australian association sought and was granted a license for the CFP designation and subsequently established the Diploma of Financial Planning (DFP) course. This necessitated strong collaboration between the United States and Australian bodies with the College of Financial Planning in the United States providing much of the DFP educational materials and resources. The US IAFP oversaw and closely monitored the development of educational standards to ensure that the Australian DFP met the educational requirements for the CFP designation. This involved an ongoing process of quality assurance by the U.S. body". It is e stimated that there are about 5,500 financial planning practices in

Substance Abuse - Alcohol and Drugs Essay Example for Free

Substance Abuse Alcohol and Drugs Essay World Health Organization has played a huge role in the management of substance abuse and its prevention especially among the vulnerable groups. It has supported countries to reduce and prevent problems caused by the use of psychoactive substances in terms of regulations and policy implementation. Its main mandate is to; â€Å"recommend reduction and prevention mechanisms which can able to prevent relapse and assess substance that highly contribute to relapse hence able to advise the U.N on what regulations to pursue†. The department of Mental Health and Substance Abuse under it has been mandated to overlook issues of curbing relapse and also substance abuse in general (Laws and Ward, 2000). The World Health Organization (WHO) defines substance abuse as â€Å"the harmful or hazardous use of psychoactive substances which include illicit drugs and alcohol†. A prolonged or repeated use of such substances can lead to addiction which is usually evident with continued use of the substances despite the fact that physical and mental deterioration is being noticed. In fact, various researchers in the world have come up with different conclusions and suggestions regarding the causes, effects, solutions and recommendations on how to deal with substance abuse (Laws and Ward, 2000). Substance abuse is a global issue. Reports reveal that the illegal drug business accounts for $400 billion of world trade, and is second only to the worldwide arms market, it is larger than the global iron and steel industries.(Cherry, Dillon, and Rugh, 2002) The 2000 World Drug Report noted that there were at least 180 million drug abusers globally, including 9 million heroin addicts, 29 million amphetamine users, and 14 million cocaine users (ODCCP, 2000)(Cherry, Dillon, and Rugh, 2002). Untreated cases of substance abuse, addiction and relapse add significant effects to communities and families. â€Å"The main effects that can be immediately noticed are; property and violence crimes, criminal and court related costs, health care utilization costs, lack of child support, prison   expenses for the government, welfare and foster care costs, child abuse, unemployment and emergency room visits† (Marks, A. Donovan, 2005). Treatment options Scientific research which has been conducted in the past have shown that effective treatment from substance abuse can help people completely recover from destructive behaviors after undoing   treatment or recovery process from substance abuse. People can successfully remove themselves from a life of substance abuse through effective treatment and long-term commitments. It includes the following; Pharmacotheraphies To a greater or lesser extent, certain drugs and alcohols have been developed and manufactured to assist in solving issues of relapse. They include opioid medications such as methadone, buprenorphine, morphine, oxycodone etc. which have been used as remedies of relapse. One of the most successful ones include bogaine which, according to medics, can help reduce the temptation of going back to substance abuse and is specifically suited for narcotics and alcohol. It is believed to interrupt  Ã‚   both psychological cravings and physical dependence on stimulants, nicotine and alcohol. Other antidepressants are able to moderate substance use particularly narcotics. All these Pharmacotheraphies have helped in the reduction of addiction and relapse of substance abuse for all genders. Rehabilitation Most of the judicial systems have been able to convict substance abusers to rehabilitation programs and to cope with withdrawal symptoms. The detoxification process of addiction involves the abrupt cessation of drug use and physical tolerance of the temptation. Medics promote the use of rehabilitation strategies to minimize effects of relapse since it is a slow but sure process of withdrawal. The method involves the use of psychological dependency which attempts to teach and train the victim new methods of freely interacting with a drug-free environment and avoid relapse. Isolation of victims or patients of relapse from people who are still substance abusers is very important as it prevents them from admiring the practice. In some organizations, moderations are utilized to allow substance abusers to re-examine their habits and compare themselves before and after stopping the practice. Many other programs utilize rehabilitation initiatives to make their initiatives more effective (Pham-Kanter, 2001). Justice systems Drug involved offenders have frequently been cycled through the judicial system whereby the substance abusers have become common to probation officers and police officers. This is an evidence that relapse is common and that the judicial system is doing very little to address it. As jails, prisons, juvenile detention centers and other correctional facilities get congested, all stakeholders in the medical field are examining newer solutions to prevent relapse. One of them is the criminal justice settings where substance abusers who are most likely to be criminals are only allowed to re-enter back into the community when they have completely recovered from substance abuse and are not likely to be affected by relapse. Relapse Prevention Therapy RPT was originally designed as a maintenance program for replace victims. It entails treatment of addictive behaviors which is used as stand-alone program that in most cases is designed to teach individuals to try and maintain changes initiated in the treatment process. Every individual has an effective response system to cope with incidences of high risk situations but the problem is the guts to do so. Post-implementation survey on suitability of RPT has shown that relapse had decreased significantly as a result of the program. RPT strategies are categorized to three groups; lifestyle modification, coping skills training and cognitive therapies. All of these strategies round up to both cognitive and behavioral techniques and approaches that provide victims of relapse with ways to reframe their habits once more and change processes in learning experiences with setbacks on how they can meet challenges of recovery. Life modifications strategies include; exercise, spiritual practices, meditation among others (Pham-Kanter, 2001). Side Effects of Addiction The most common side effect of substance abuse i.e. alcohol and drug is what is termed as substance relapse. Relapse is a situation of ‘converting back’ from a condition after a short or long abstinences. In drug addiction and substance abuse, it can be defined as â€Å"the resumption of the use of drugs after leaving it for some time† that is according to World Health Organization in the year 2004 (Laws and Ward, 2000). Substance abuse relapse is a condition where one feels to have failed to recover fully from addiction to drugs or substance abuse despite the fact that they have gone under a professional recovery plan. It means that individuals are tempted to use the drugs even after they have undergone a medical response process. Relapse to substance abuse is a common problem that can have devastating effects on the victim especially physical and emotional impacts. It requires good communication and counseling between the counselor and the patient. Recovery from substance abuse especially is not a complete failure to eradication but a step further; in real sense, a positive way to strengthen the process of recovery that is difficult to address given the complexity nature of the issue. There are three ways of severity of relapse which is normally used to determine the most suitable medical or counseling response. The first level is slip where the victim briefly resumes drug use but have no signs of drug dependence or symptoms of addiction.   The second level is several level of drug abuse. This is the most severe form because the victim resumes substance abuse for several days during the treatment process. This should be used as a learning process where the patient should learn from experience and prevent further relapse. The last level is the sustained drug use evidenced by resumption of addiction. The victims of substance abuse fully relapse to addiction and eventually drops out treatment and those medics and counselors need to start from scratch (Marks, A. Donovan, 2005). The Relapse Process Any use of a substance after a period of abstinence is a measure of the relapse rates. Previous research has indicated that temporal patterning of the relapse process and that the circumstances under which the process occurs across all the genders is under is difficult to comprehend especially by unprofessional persons and the victims themselves. Hence the commonalities across all substance abusers are an indication of the relapse rates and it involves a sense of perceived control and self-efficacy (Marks, A. Donovan, 2005).       Reference Cherry, A, Dillon, M, Rugh, D (2002): Substance abuse a global view. Westport, Conn: Greenwood Press Laws, D. Ward, T. (2000): Remaking relapse prevention with sex offenders: The sourcebook. Newbury Park, CA; Sage Publications Marks, A. Donovan, D. (2005): Relapse prevention; Maintenance strategies in the treatment of addictive behaviors (2nd Ed.). New York: Guilford Press Pham-Kanter, G. (2001): Substance abuse and dependence. The Gale Encyclopedia of Medicine Second Edition Farmington Hills, MI: Gale Group,

Impact of Weather on Dengue Disease

Impact of Weather on Dengue Disease Dengue is the most tropical infectious disease that is transmitted by the Aedes aegypti mosquito. The dengue disease incidence rises as a serious public health problem with 2.1 billion people at risk. In Malaysia, the dengue disease over the last 40 years has become worst epidemic in the countrys history. This study aimed to analyses relationship between weather parameters and increase of dengue incidence among university Putra Malaysia students, to identify the direct or indirect effect of weather on dengue incidence and to determine the relationship of dengue disease located in UPM (SERDANG). The objective of this study was to assess the effect of meteorological parameters variation on the dengue virus transmission between UPM students. We obtained data on monthly weather parameters including relative humidity and median mean temperature and rainfall amount and monthly dengue cases. Analysis was conducting by employing correlation and regression, plotting. A total of 7 years of den gue occurrences since 2005 to 2011 were plotted, 2005 and 2010 were the highest years with dengue cases rates while, 2006 and 2007 were the lowest dengue incident rates. Analysis of monthly mean temperature data for UPM indicated that the months which having very warm days has higher dengue rates while, the precipitation months has more direct effect on these rates. On the other hand, humidity is the most factors have highest impact on dengue incidence between UPM students. Keywords:  Weather impact, dengue incidence, UPM students. INTRODUCTION Dengue fever (DF) and Dengue hemorrhagic fever (DHF) possess recurred as 1980s and rapidly come to be a main epidemiological menace worldwide; especially in South East Asia and Western Pacific Region. Dengue fever is rampant in more than 120 countries alongside approximated 2.4 billion populations at the chance and annual dengue infection of 52 million cases according to World Health Organization, (WHO, 2005). Of this, Asia Pacific Area shares the biggest burden of dengue alongside approximated above 75% of the 2.5 billion populaces at chance living in the region. As yet, the particular causes for the re-emergence of dengue are not completely comprehended. Though, the U.S. centers for Disease Control and Prevention has recognized factors such as weather factors and accelerated urbanization, poor areas, increased global excursion, and lack of competent vector manipulation arrangement as a few of the main determinants that possess gave globe rise of DE/DHF as a main area condition burd en (U.S. C.D.C.P,2007). In Malaysia Dengue considered as endemic disease with four serotypes of dengue viruses. Dengue is the most threaten disease to public health in Malaysia. Around the world 50 million cases are reported each year about the dengue disease infection (WHO, 1999). Dengue is endemic in Malaysia the first case was recognized in Penang 1902, while the first dengue hemorrhagic fever outbreak was reported in 1962, likewise in Penang (Ska, 2006). . In the year 2005 MALAYSIA experienced the worst past outbreak of dengue incidence alongside 326.5 cases each 100,000 populations. The overall dengue cases in Malaysia augmented from (39,597 person) and (84 person deaths) in 2009 to (45,037 person) and (133 person deaths) in 2010 (HM, 2010). It is notifiable that Selangor state has the highest (dengue cases) followed by (Johor and Sarawak) for 2010 (MOH, 2010). The urban and also rural areas of Malaysia are the greatest predominant habitations for the spread of the (yellow fever mosquito) species which is Aedes aegypti (Mohd et al., 2006). The mosquitoes of yellow fever can be found in the area of stagnant water and also in severe drainage (Mohd et al., 2006). The patients of dengue will suffer symptoms include vomiting, rashes on the skin, headache, nausea and muscle pain (NCID, 2005). Recent Studies have shown that temperature could have an impact on feeding characteristics, population size, maturation period and survival rate of Aedes mosquitoes and pupae, and larvae mature female mosquitoes mortality rate as a function of temperature Between 11  °C and 42 °C. (Hii, Y et al .2009). Many Studies shown that the high temperature have an impact on the population magnitude and maturation period, the survival rate of Aedes mosquitoes and the Feed characteristics. Aedes mosquitoes on temperature which ranging from 16 °C to 31 °C, experience lower mortality rates , a study in French Guiana illustrated that at favourable environment condition Aedes mosquitoes capable to live 76 days . On the other hand, heavy rain decrease survival rate of female mosquitoes and destroys larvae in short time but in long term, it creates plentiful breeding resources. Simultaneously, Aedes mosquitoes at a higher temperature 32 °C rises feeding frequency more than twofold compared to the temperature at 24 °C. Extremely Low rainfall rates will increase surroundings temperature, usage of water storage and water and air-coolers may serve as breeding habitats. Finding the relationship between weather factors mainly (temperature, rainfall, humidity) It can be useful for prioritizing prevention in public health sector decision making.. A threat prediction of dengue outbreak can be produced so local health officials can expect the number of cases and make proper strategy to control it. Example The dengue disease epidemic has become more serious problem in serdang with increasing about 14 percents for 2011 (Mstar, 2011). Selangor state recorded highest cases of dengue incidence compared to other states (MOH, 2010). For Seri Kembangan area, the dengue disease epidemic noted the 75 cases on 2009 while for year 2010, a total of 158 cases were reported (Mstar, 2011). The major source of Aedes mosquito breeding is in factories, abandoned housing projects, from the construction sites and vacant plots land (Thammapalo et al., 2001). The aim of this study an association amid dengue incidence and mean temperature, humidity and rain also more discuss how meteorological conditions impact on the rise of dengue in Universiti Putra Malaysia across the period 2005-2011 and to identify the most high risk years with dengue incidence. The result of this study will be highlighting the connection between dengue cases and weather parameters within Seri kambangan 2005 2011. Health sector planners and policy makers benefit from this kind of studies as it generates useful information which further can be used for the creation of schematic approaches for disease prevention, interceptive studies and control programmes. This study is important as it can help in delaying or reducing the incidence of disease and its related socioeconomic implications at the individual and the community level as a whole. Results achieved were used to recognize the patterns of dengue cases and the degree of dependence of dengue incidences on the weather parameters. In this study, we tried to provide additional details on relationship between dengue rates with weather parameters. Attention was focused on four years with lowest dengue incidence (2006 and 2007) also the highest two years with dengue cases (2005 and 2010) were inspected, and statistical analysis has been done to find evidence on the degree of correlation between the dengue and climate factors (precipitation, relative humidity ,temperature). METHODOLOGY 2.1 Study area Universiti Putra Malaysia is a public school which is approximately 22 km south of capital city Kuala Lumpur by road which located at latitude of 2 °59 ´57Ë  N and longitude of 101 °42 ´28Ë  E. The main campus of UPM is located at Serdang, Selangor state which cover an area of 1,200 hectares of spectacular natural landscape and the topography is between 49m to 52m above sea level (figure 1). Universiti Putra Malaysia has a population of 29,724 in first semester of 2011/ 2012 session. The staff population is 6,100 that include academic, non-academic and sporting staff while that of student is 23,624 which include post graduate and undergraduate students. Out of the total population of students, only 14,108 are residing on campus while others stay off campus. The Malaysian peninsula has a typical equatorial climate characterized by constantly high annual temperature and heavy rainfall. Temperature range is practically the same all over Malaysian peninsula throughout the year and is only governed by the height of the land above sea level; there are important differences in the amount and seasonal distribution of the rainfall in different part of the country. An average mean rainfall is about 2489mm which distributed throughout the year, with the bulk of the rain concentrated in the month of October and November, and its rains comparatively less in May to September (dry season) than October to April (wet season).Monthly average temperature are high on the month of April and May while December and January are the months with the low average temperature. Mean daily dry season (May to August) temperature range from 31 °C to 34 °C and the mean daily wet season (November to February) temperature range from 29 °C to 32 °C. 2.2 Data Source The Weather parameters data of UPM (2005- 2011) was obtained from Malaysian meteorological department (MMD). Temperature had estimated This data was distributed into monthly data per year. This parameters which include (rainfall, humidity, mean maximum temperature) has been used to understand degree of dengue fever dependence on weather parameters (Morrison et al., 1998). Dengue epidemiological data monthly basis and annually was obtained from UPM PUSAT KESIHATAN from (2005 to 2011). dengue haemorrhagic fever (DHF) or dengue fever (DF) were recognized as clinical dengue cases with confirmed laboratory blood tests of dengue viral infection of any serotypes Under the Infectious Diseases Act in Malaysia, it is needed for all medical practitioner must inform all confirmed or recognized dengue cases within 24 hours to the Ministry of health. (Infectious Disease Prevention and Control Act 1988). The only data which obtained from UPM PUSAT KESIHATAN were number of monthly and annual cases. 2.3 statistical analyses All the dengue cases were plotted in the graph by using Minitab 16 version. Calculating and investigating the variability of rainfall, humidity and temperature indices, creating scatter plots and charts of Dengue fever cases against meteorological conditions variables, correlation analysis.( Amarakoon et al.,2004). Here we analysed the association of rainfall and temperature, Humidity alongside dengue transmission in every single year in University Putra Malaysia. We only exclude 3 years owing to the very small dengue cases. The cases of dengue disease were examined includes geographic distribution and spatial gender distribution (Srivastava et al., 2009). The purpose of geographic distribution is to determine the distribution of dengue cases among Kuantan district. Apart from that, the gender distribution was categorized into two groups which were male and female. The statistical significant between both gender were analyzed by using t-test. 2.3.1 Spatial distribution The spatial distribution of dengue incidence within concession of Kuantan was observed. The spatial autocorrelation method measures the relationship among values of variable according to the spatial arrangement of the values (Chang, 2010). The Morans I method was selected to test whether the dengue cases within Kuantan district is spatially correlated or not (Er et al., 2010). The area units where numerical ratio or interval data were available were the area where the Morans I normally applied (Nakhapakorn Jirakajohnkool, 2006). It considers both point locations and variation of an attribute at the location and finally it can evaluate whether the pattern of dengue cases within Kuantan district were clustered, dispersed or random. The Morans I measure can be compute by (Er et al., 2010): Where N is the number of cases, is the mean variables, is the variable value at particular location I, Xj is the variable value at another location j, and Wij is a weight indexing location of I relative to j. in Morans I range, a strong negative spatial autocorrelation is in the range of -1 and a strong positive autocorrelation is in the range +1. The value 0 means it is spatially random pattern. 2.3.2 Distance Analysis The Average Nearest Neighbour (ANN) is one of the techniques for point distance analysis. It was used to analyzed the distance between each point, to determine whether the point pattern is clustered, random or regular (Clark Evans, 1994). In this study, the ANN was tested to predict whether the dengue incidence is cluster or not. The ANN analysis predicts the distance between each feature centroid and its nearest neighbour centroid. If the average distance is less than 1, the point pattern was considered clustered whereas if the average distance is greater than 1, the point was considered dispersed. The average nearest method is computed by: (1) Where is the observed average distance between each feature and their nearest neighbour. is the expected average distance for features given a random pattern. The average neighbour analysis also can produce the ZANN score, which indicates the likehood that the pattern could be a result of random chance. The ZANN score is computed by: (2) Where: (3) 2.3.3 Buffer analysis Buffering is a system operation that generates zones that consist of area within the specific distance with selected features (Chang, 2010). In this study, buffering was conducted to determine the extended neighbouring buffering method is used. The 500 meter radius of buffer were carried out from the dengue disease cases point as the mosquitoes flies at the maximum distance of 600 meter from the breeding site (Madanayake et al.,2010). A study conducted by de Freitas and de Olivera (2009) found that 50%-90% of female A. Aegypti flew up to 350 meter and 500.2 meter and their maximum displacement was 690 meter. 2.3.4 Hot Spot Prediction The Kernel density estimation interpolation was used to predict the hot spot locality (Jeefoo et al., 2011). Kernel density estimation is one of the method that applied to identify high risk areas within point patterns of disease incidence and also can defines the level of the high risk of that area (Bithell, 1990). Kernel density estimation is an interpolation that compatible for single point locality. The Kernel density estimation is the better hot spot identifier than cluster analysis. It can measures the density of point feature in each of the output raster cell .This method has been applied in previous study on spatial mapping on dengue disease to locate hot spot for dengue cases in the district of Hulu Langat (Er et al., 2010). Jeefoo et al, (2011) has used the kernel density to locate the spatio-temporal diffusion of dengue pattern and prove that the hot spot area have an influence on the spread of an infectious disease. RESULTS AND DISCUSSION 3.1. annual Dengue incidence years (2005-2011). During the study time, dengue cases (Fig. 1) increased from 37 cases were reported in year 2006 to 75 cases reported in 2009, after which, annual reported dengue cases have amplified alongside greater temperature and humidity alongside record of 52 cases in year 2008 and peaked in year 2005 alongside 159 cases. The incidence next cut to 40 cases in 2007 and resurged in 2011 alongside 48 cases. In the study period the highest dengue cases were described in August of year 2010 with 44 cases. The extremely months with high dengue occurrence were between July December. Results obtained in this discover are given in tables 1 to 4, and figures 1 to 12. Tables contain results for correlation of dengue occurrences alongside meteorological conditions parameters. While, figures show relationship between weather factors and dengue cases. reveals period sequence of weekly meteorological conditions predictors and dengue cases. Singapore experienced the highest weekly mean temperature of 30.48C in year 2005 followed by 30.38C in year 2002. The highest weekly mean temperature in the discover era was recorded in week 17 of year 2005 alongside zero weekly cumulative precipitation. As the most extended dry spell of 40 dates transpired in the early two months of 2005, highest weekly cumulative precipitation was recorded as 388 mm in week 51 of year 2006. Overall, weekly mean temperature for year 2000-2003 fluctuated from 25.7 to 30.38C; as the scope was 25.530.48C for 20042007. Concurrently, weekly cumulative rain in years 20002003 fluctuated from 0 to 260 mm alongside average 42 mm and the scope was 0388 mm alongside average 44.5 mm for years 20042007. Our results of this study indicates that precipitation and temperature were positively associated with monthly dengue cases informed in University Putra Malaysia (Table 1) which mean they seems to have played an important role in increase of dengue cases . Although, humidity hazy days and foggy days were have suspicious association with dengue cases occurrence but still not powerful as other parameters. 3.2 Correlation and Regression coefficients. Both Humidity and Temperature display positive role in cases number and the humidity shows suspicious response with high significant effect (P-value Correlation results are very significant in relation to mean maximum temperature (P-value = 0.860) and dengue occurrences. It is clear that rainfall associated with dengue cases (R ² = 85.5) which mean 85.5 % rainfall associate with dengue cases. In particular mean median humidity seems to have moderate positive role in dengue transmission compared to the other variables with (P-value = 0.779) and (R ² = 60.7) Figure 1, simplify rainfall amount for year 2006, shows that the precipitation playing very strong contributor factor for increase and decrease of dengue cases, while box plot confirms table 1 results (p-value) which is represents the percentage of total rainfall vs. dengue occurrence. Even though rainfall scale has increased over the last seven decades precipitation does show statistically significant (r square = 92.0 and p- value = 0.970). As shown in Fig. 2, dengue rate has increased linearly with monthly mean temperature at January and December with 7 and 6 cases as temperature increasing; plot confirms that temperature is participating factor of transmission of dengue virus owing to the positive relationship between temperature and dengue cases . Simplify relationship between humidity and dengue cases. As Fig3 illustrated humidity play doubtful contributor of increasing dengue diseases occurrence. From 70.1 % to 71.1% only one case has been recorded, while percentage of fogy months increased cases of dengue rises instantly. At 74.1 per cent 4 cases were informed and 7 dengue cases when humidity reached 76.3%. CONCLUSION The weather factors that affected the rising of dengue disease incidence have been identified, which were the temperature and humidity and rainfall. The study showed that the most weather conditions factors which contributed to the high incidence of dengue cases within UNIVERSITI PUTRA MALAYSIA area among seven years 2005-2011 were rainfall and temperature which were have very strong correlation with dengue cases. The result of the graphs plot shows that the three studied weather elements where positively associated with increase of dengue cases among students of UNIVERSITI PUTRA MALAYSIA area and The data presented in this study are important because it give baseline information on the main factors contributed of transmitting dengue virus for a particular zone. It is recommended that collecting forecasting data for the three specific factors to predict potential future cases to make efficient plan to control dengue transmission in case of epidemic and expect the number of dengue occurrence. When these strategies are implemented, the diverse costs associated with dengue cases will decrease. All of these results should be considered in the future patterns prediction of dengue transmission. Early warnings of dengue epidemics based on climate information are effectively communicated to public health decision makers and Climate accounts for some variation in dengue risk, Important to account for confounding factors. For future work incorporate better understanding of disease transmission process. The lack of information about specific factors which playing main role of high dengue disease incidence will lead to improper Vector surveillance and control management in case of dengue outbreak in specific zone and may loss many of lives. Understand connection between weather and dengue transmission will develop capability of national dengue management and diagnostic and impacts assessment of dengue mosquito vectors. The spatial distribution of dengue incidence within Kuantan district for 2011 has been mapped included geographic distribution and gender distribution. The geographic distribution has shown the highest distribution of dengue cases in Kuantan. The gender distribution has revealed that male population has the higher incidence of dengue cases. The buffer analysis was conducted to see the most high risk area for dengue fever incidence. It was identified that the high risk area were 500 meter radius from the dengue cases incidence. By using the statistical analysis, the pattern of spatial distribution of dengue incidence can be determined by spatial autocorrelation and was supported by distance analysis. The hot spot locations for dengue incidence were located by using kernel density estimation. As a conclusion, the Geographic Information System (GIS) provided a very useful tool in the health mapping. Furthermore, the GIS has played an important tool for effective surveillance and prediction of the dengue outbreak in order to reduce the number of dengue cases. Acknowledgement The author thanks to University Putra Malaysia (UPM), Kuantan District Health Office Pahang, Department of Town and Country Planning ,Kuantan who provided the data and advices. Anker, M. Arima, Y. 2011. Male-female differences in the number of reported incident dengue fever cases in six Asian countries. Western Pacific Surveillance and Response Journal. 2:2. doi:10.5365/wpsar.2011.2.1.002. Barrera, R., Delgado, N. Rogi, M.G., (2000). Stratification of a city with hyperendemic dengue hemmorrhagic fever. Retrieved on 6th November, 2010 from http://www.popline.org/docs/1354/153852.html Bithell, J.K. 1990. An Application of density estimation to geographical epidemiology. Statistics in Medicine.,9,691-701 Chang, K.T. 2010. Introduction of Geographical Information System. New York: McGraw Hill. Clark, P.J., Evans, F.C. 1994. Distance to nearest neighbour as a measure of spatial relationships in populations. Ecology. 35:445-453 Curriero, F.C., Patz, J.A., Rose, J.B Subhash, L. 2001. The association between extreme precipitation and waterborne disease outbreaks in United States. American Journal of Public Health. 91(8): 1194-9 Eong, O.E. 2001. Changing pattern of dengue transmission in Singapore. Dengue Bulletin,2001, 25:40-44 Er, A.C., Rosli, M.H., Asmahani, A., Mohamad Naim, M.R. Harsuzilawati, M. 2010. Spatial mapping of dengue incidence: a case study in Hulu Langat District, Selangor. International Journal of Human and Social Sciences. 5(6):410-414 Halstead, S.B. 1995. Dengue in the health transition. The Kaohsiung Journal of Medical Science. 10:2-14 Harian Metro,2010. Kes Denggi meningkat,133 kematian tahun ini. http://www.harian-metro-online.com./kes-denggi-terus-meningkat-tahun-ini (retrieved on 23 October 2011) Jeefoo, P., Tripathi, N.K., Souris, M. 2011. Spatio-Temporal Diffusion Pattern and Hotspot Detection of Dengue in Chachoengsao Province, Thailand. Int. J. Environ. Res. Public Health 8:51-74; doi:10.3390/ijerph8010051 Madanayake, M.P, Gunatilake, J., Haji, A., Iqbal, M.C.M. 2010. A GIS approach to generatea dengue risk map. Msc. Thesis. University of Peradeniya, SriLanka. Martinez, R. 2006. Geographic information system for dengue prevention and control. Working paper for the Scientific Working Group on Dengue Research, convened by the Special Programme for Research and Training in Tropical Diseases, Geneva, 1-5 October 2006 Mohd, D.M.A., Shaaban, M.G., Taib, N. Leman, N. 2006. The study of dengue disease by GIS software in urban area of Petaling Jaya Selatan. International Conference in GIS and public Health. Hong Kong, June 27-29. Pp16. Morrison, A.C., Getis, A., Santiago, M., Rigau-Perez, J.G. Reiter, P. 1998. Exploratory space-time analysis of reported dengue cases during an outbreak in florida, puerto rico, 1991-1992. Am. J. Trop. Med. Hyg., 58(3): 287-298. Mstar,2012 More dengue campaigns in schools and residential areas , SERI KEMBANGAN http://thestar.com.my/news/story.asp?file=/2012/3/5/nation/10854555sec=nation (retrieved on 5 March 2012) Nakhapakorn, K., Jirakajohnkool, S. (2006). Temporal and spatial autocorrelation statistics of dengue fever. Dengue Bull 30: 177-183. Nakhapakorn, K. Tripathi, N.K. 2005. Using GIS technology to identify risk area of dengue fever (DF) and dengue haemorrhagic fever (DHF). 8th Annual International Conferences, Indonesia, August 22-26 National Centre for Infectious Diseases, 2000. Travellers Health. Virginia. Otero, M., Solari, H.G. Schweigmann, N. 2005. A stochastic population dynamics model for Aedes aegypti: formulation and application to a city with temperate climate. Bulletin of Mathematics Biology. Pejabat Tanah Jajahan Kuantan,2011. http://ptjk.pahang.gov.my/keluasan.php (accessed 18th March 2012) Skae, F.M 1992. Dengue fever in Penang. British Medical Journal. 2:1581-1582. Shekhar, KC. Huat, O.L. 1993. Epidemiology of dengue/dengue hamorrhagic fever in Malaysia-A retrospective epidemiology study 1973-1987. Part I: Dengue hemorrhagic fever (DHF). Asia-pasific Journal of Public Health,6:15-25 Srivastava, A., Nagpal, B.N., Joshi, P.L., Paliwal, J.C., Dash, A.P. 2009. Identification of malaria hot spots for focused intervention in tribal state of India: a GIS based approach. International Journal of Health Geographics, 8:30 doi:10.1186/1476-072X-8-30 Thammapalo,S., Chongsuwiwatwong, V., McNeil,D. Grater, A. 2005. The climate factors influencing the occurrence of dengue haemarrhagic fever in Thailand, Southeast Asia. Journal of Tropical Medicine and Public Health. 36 (1):191-7 Tran, A. Deparis, X. et al., 2004. Dengue spatial and temporal patterns, French Guiana, 2001. Available from:http://www.cdc.gov/ncidod/EID/vol10no4/03-0186.htm retrieved 6th November, 2010. Wagatsuma Y., Ali, M., Emch, M. Breiman, R.F. 2003. Use of a geographic information system for defining spatial risk for dengue transmission in bangladesh: role for aedes albopictus in an urban outbreak. Am. J. Trop. Med. Hyg., 69(6): 634-640. World Health Organization, WHO 1997. Dengue haemorrhagic fever: Diagnosis, treatment, prevention and control, 2nd Edition. Geneva World Health Organization, WHO 1999.Strengthening implementation of the global strategy for dengue fever and dengue haemorrhagic fever, prevention and control. Report of the Informal Consultation. Geneva, October 18-20 Yew, Y.W. 2009. Seroepidemiology of dengue virus infection among adults in Singapore. Annals of the Academy of Medicine. 38:667-275 Hii, Y., Rocklà ¶v, J., Ng, N., Tang, C., Pang, F., Sauerborn, R. (2009). Climate variability and increase in incidence and magnitude of dengue incidence in Singapore. Global Health Action, 2. doi:10.3402/gha.v2i0.2036 Notification requirement under section 10(2) Infectious Disease Prevention and Control Act 1988.

Statistical techniques for cryptanalysis

Statistical techniques for cryptanalysis Introduction: Cryptography is the art of writing messages in code or cipher, to disguise, and thereby secure the content of a particular stream of text. When encrypted, a plain text message can be revealed only through the use of the key used to encode the cipher. Cryptography does not mask the existence of the message, but does disguise its content [1]. In contrary, cryptanalysis is the art of recovering the plaintext of a message without access to the key. Successful cryptanalysis may recover the plaintext or the key for a specific ciphertext [2]. There are five general types of cryptanalytic attacks:- 1. Ciphertext-only attack: In this type of attack, the cryptanalyst has a series of cipher texts encrypted using the same encryption algorithm. Then, the cryptanalyst deduces the plain text of each of the cipher texts or identifies the key used to encrypt the cipher text 2. Known-plaintext attack: In this type of attack, the cryptanalyst has a series of ciphertext and their corresponding plaintext values encrypted using a specific key. The cryptanalyst then tries to deduce the key by forming a relationship between the ciphertext and plaintext entries. 3. Chosen-plaintext attack: In this type of attack, the cryptanalyst not only has access to the ciphertext and associated plaintext for several messages, but he also chooses the plaintext that gets encrypted. His job is to deduce the key used to encrypt the messages or an algorithm to decrypt any new messages encrypted with the same key. 4. Frequency analysis: It is the study of thefrequency of lettersor groups of letters in aciphertext. The method is used as an aid to breakingclassical ciphers. Frequency analysis is based on the fact that, in any given stretch of written language, certain letters and combinations of letters occur with varying frequencies. 5. Rubber-hose cryptanalysis: The cryptanalyst threatens, tortures or blackmails the person who has the key until they give it up. Among the many cryptanalytic techniques, frequency analysis or frequency counting is the most basic technique applied to break substitution cipher based algorithms, among the varied list of attack techniques. The basic use of frequency analysis is to first count the frequency of ciphertext letters and then associate guessed plaintext letters with them. More complex use of statistics can be conceived, such as considering counts of pairs of letters digrams, trigrams, and so on. This is done to provide more information to the cryptanalyst. It exploits the weakness in the substitution cipher algorithm to encrypt similar plaintext letters to similar ciphertext letters. Frequency analysis based cryptanalysis techniques were used to break ciphers based on the traditional cryptographic algorithms, but they do not work well with the modern block cipher based cryptographic algorithms. Statistical properties of English: Frequency analysis based cryptanalysis uses the fact that natural language is not random in nature and single alphabetic based substitution does not hide the statistical properties of the natural language. In the case of encryption using monoalphabetic substitution, to start deciphering the encryption it is useful to get a frequency count of all the letters. The most frequent letter may represent the most common letter in English, E followed by T, A, O and I whereas the least frequent are Q, Z and X [7]. Statistical patterns in a language can be detected by tracing the redundancy of the text in the language. It has been realized that various universal regularities characterize text from different domains and languages. The best-known is Zipfs law on the distribution of word frequencies [5], according to which the frequency of terms in a collection decreases inversely to the rank of the terms. Zipfs law has been found to apply to collections of written documents in virtually all langu ages [5]. English language characters have a very high redundancy rate when used for cryptographic substitutions. If we have a message encrypted using the substitution cipher that needs to be cracked, we can use frequency analysis. In other words, if the sender has used an encryption scheme, that replaces one letter in the English to be another letter in English, we can still recognize the original plain text as, the frequency characteristics of the original plain text will be passed on the new cipher text characters [4]. To apply frequency analysis, we will need to know the frequency of every letter in the English alphabet, or the frequency characteristics of the language used by the sender to encrypt the text. Below is a list of average frequencies for letters in the English language. So, for example, the letter E accounts for 12.7% of all letters in English, whereas Z accounts for 0.1 %. All the frequencies are tabulated and plotted below:- For example, let us consider the following sentence: We study Cryptography as part of our course. Using a simple substitution cipher, let us consider the following: a->c , b-> d, c->e..w->y, x->z, y->a, z->b So, the cipher text becomes: yg uvwfa etarvqitcrja cu rctv qh qwt eqwtug. A simple frequency analysis of the cipher text can be carried out and the results are as given below: The above data can be used by a cryptanalyst to identify the key or the plaintext by using simple substitution to the cipher text till a suitable plaintext value is not identified. Apart from the use of mono alphabetic frequency analysis, cryptanalysts also identify frequency of paired letters better known as digram frequency and that of three letter words, called as Trigram frequencies. These help the cryptanalyst to exploit the redundant features of English language to break the cipher. The most common Digrams (in order): th, he, in, en, nt, re, er, an, ti, es, on, at, se, nd, or, ar, al, te, co, de, to, ra, et, ed, it, sa, em, ro. The most common Trigrams (in order): the, and, tha, ent, ing, ion, tio, for, nde, has, nce, edt, tis, oft, sth, men Table 1: Digram and Trigram Frequencies [6] These help in identifying the most commonly used terms in English to break a cipher. The digram frequencies are used to break two letter words such as an, to, of etc and the trigram frequencies are used to break three letter words such as the, are, for etc. After breaking a significant two letter and three letter words, it is practically east to identify the key from the cracked values of plaintext by matching the corresponding values in the ciphertext. This huge weakness in English language is used to break cipher texts encrypted using simple algorithms that make use of English alphabets. In practice the use of frequency analysis consists of first counting the frequency of ciphertext letters and then assigning guessed plaintext letters to them. Many letters will occur with roughly the same frequency, so a cipher with Xs may indeed map X onto R, but could also map X onto G or M. But some letters in every language using letters will occur more frequently; if there are more Xs in the c iphertext than anything else, its a good guess for English plaintext that X is a substitution for E. But T and A are also very common in English text, so X might be either of them also [4]. Thus the cryptanalyst may need to try several combinations of mappings between ciphertext and plaintext letters. Once the common single letter frequencies have been resolved, then paired patterns and other patterns are solved. Finally, when sufficient characters have been cracked, then the rest of the text can be cracked using simple substitution. Frequency analysis is extremely effective against the simpler substitution ciphers and will break astonishingly short cipher texts with ease. Attacks on Traditional algorithms Encrypting using traditional algorithms have been defenseless against cryptanalytic attacks as they use bit by bit encryption, which can be easily broken using frequency analysis based attacks. 1. Caesar Cipher: Considering the case of one of the oldest ciphers, the Caesar Cipher, this cipher replaces one letter of the plaintext with another to produce the ciphertext, and any particular letter in the plaintext will always, turn into the same letter in the cipher for all instance of the plaintext character. For instance, all Bs will turn into Fs. Frequency analysis is based on the fact that certain letters, and combinations of letters, appear with characteristic frequency in essentially all texts in a particular language [9]. For instance, in the English language, E is very common, while X is not. Likewise, ST, NG, TH, and QU are common combinations, while XT, NZ, and QJ are very uncommon, or even impossible to occur in English. This clearly shows how the Caesar cipher can be broken with ease by just identifying the frequency of each letter in the cipher text. A message encrypted using Caesar cipher is extremely insecure as an exhaustive cryptanalysis on the keys easily breaks the code. 2. Substitution Ciphers: The Caesar cipher forms a subset of the entire set of substitution ciphers. Here, the key of the encryption process is the permutation of all the twenty six characters of the English alphabets. Rather than choosing a particular key for all encryption process, we use a different key for successive encryption processes. This technique increases the number of possible key to 26!, which is about 4 X 1026, which eliminates the exhaustive cryptanalysis attack on the keyspace [7]. To decrypt the cipher the, statistical frequency distribution of single letter occurrence in English language is analyzed. Then, the digram and trigram frequencies of standard English words are compared with the frequencies of the trigrams in the cipher to finally reconstruct the key and in turn decipher the text. This is an efficient method to break the substitution cipher as, each plaintext letter is represented by the same ciphertext letter in the message. So, all properties of plaintext are carried on to the cipher text. 3. Vigenere Cipher: In a Vigenere cipher, there is greater security as, a given plaintext letter is not always represented by the same ciphertext letter. This is achieved by using a sequence of n different substitution ciphers to encrypt a message. This technique increases the possible number of keys from 26! to (26!)n. Although this was considered to be unbreakable, the Kasiskis method of attacking a Vigenere cipher yielded successful results of decrypting the message. According to this method, the first step is to find the key length (n). Find identical segments of plain text that get encrypted to the same ciphertext, when they are b positions apart, where b=0 mod n. According to Kasiski, the next step is to find all the identical segments of length greater than 3, and record the distance between them [7]. This can then be used to predict the length of the key (n). Once this is found the key is found by an exhaustive search of the keyspace for all possible combinations to identify the key. This is done by substituting all possible values for n to generate substrings. Once the substring is formed, the plaintext message can be automatically identified by using the back substitution of the key into the cipher [7]. This can be done for all possible values for n until finally arriving at the actual key, which reveals the plaintext that was encrypted. This method can take a long time to break the key to identify the plaintext incase the key length is very long, as the keyspace value would be large for larger keys. Defeating frequency based attacks: Frequency based attacks have been used for a long time to break traditional encryption algorithms. It uses the fact that, traditional encryption algorithms do not eliminate the statistical properties of the language upon encryption. The first way to defeat frequency based attacks is to encrypt blocks of characters at a time rather than single letters [7]. This would ensure that, the same text in the plaintext is not encrypted to the same text in the ciphertext upon encryption. For e.g., if we use the Caesar cipher encryption scheme, the word ADDITIONAL will be encrypted to CFFKVKQPCN, we can see that the alphabets A, D and I are repeated more than once and at each instance, the encryption scheme used always encrypts A to C, D to F and I to K. This can clearly be used during frequency analysis to analyze the redundancy of the characters and in turn map them back to get the original plaintext character. Using a block encryption scheme, one can be satisfied that, this phenomenon does not occur as, in a block encryption scheme, the whole plaintext is broken into chunks or blocks of data, that is fed in as input to the encryption algorithm. The algorithm then, reads the input block along with the key and encrypts th e complete block of plaintext, rather than individual characters, so there is a smaller chance that two blocks will produce the same chunk of ciphertext. The second way of defeating frequency analysis is to make use of synonyms of words [7], rather than repeating the same word over and over again in a sentence. There are a lot of words in English, which have more than one synonym, thus providing with a set of words to be used as convenient in the particular context. To help in the selection of a synonym, grammar checking would have to be used to ensure that, the meaning expressed in the sentence is not altered by changing the words. Attacks against this technique could include creating a list of the best synonyms, but this would not help the attacker as different word could be used at each instance the same meaning needs to be expressed, defeating the benefit of this technique. This technique of using alternate words to represent common words to defeat cryptanalysis attacks is called Homophones [7] in cryptography. A third technique that can effectively defeat cryptanalysis is Polyalphabetic substitution, that is, the use of several alphabets to encrypt the message [3], rather than using the same substitution technique again and again. The Vigenere Cipher is a form of Polyalphabetic cipher. This ensures that, no two characters are encrypted to the same ciphertext alphabet in the same message. This ensures that, direct frequency analysis of the cipher is not possible to successfully retrieve the original message. However, other techniques need to be used to identify the key length, if this is possible, then frequency analysis attack could be used to identify the original plaintext message successfully. Finally, a possible technique that could be used to defeat frequency analysis is to encrypt a single character of plaintext with two ciphertext characters [3]. Upon encountering the same character twice, then different characters should be used to encrypt the message. This can be achieved by using a key size double that of the plaintext message and then encrypting the same plaintext with two values in the key and save them together for the same plaintext character. This would ensure that no two plaintext characters will have the same ciphertext character, defeating the frequency analysis method of breaking the cipher. Modern encryption algorithms and cryptanalysis: Modern cryptographic algorithms take a better approach in defeating frequency analysis based attacks. The cryptographic algorithms nowadays use block encryption, rather than encrypting characters bit by bit, thus eliminating the redundancy of ciphertext alphabets for similar plaintext alphabets. Block ciphers are the central tool in the design of protocols for shared-key cryptography. A block cipher is a function E: {0, 1}k ÃÆ'- {0, 1}n à ¢Ãƒ ¢Ã¢â€š ¬Ã‚   {0, 1}n. This notation means that E takes two inputs, one being a k-bit string and the other an n-bit string, and returns an n-bit string [2]. The first input is the key, which is used to encrypt the secret message. The second string is called the plaintext, and the output is called a ciphertext. The key-length k and the block-length n are parameters associated to a specific block cipher. They vary from block cipher to block cipher, and depend on the design of the algorithm itself. Some of the most trusted symmetric ciphers inclu de AES, Triple-DES, Blowfish, CAST and IDEA. In public-key cryptography, the most commonly used cryptosystems are RSA and the Diffie-Hellman systems, which have not been found to have any vulnerabilities till date. Preferably, the block cipher E is a public specified algorithm. In typical usage, a random key K is chosen and kept secret between a pair of users. The function EK is used by the sender to encrypt the message, for a given key, before sending it to the intended receiver, who decrypts the message using the same key [2]. Security relies on the secrecy of the key. So, at first, one might think of the cryptanalysts goal as recovering the key K given some ciphertext, intercepted during transmission. The block cipher should be designed to make this task computationally difficult. In order to achieve this, the algorithms that are used to encrypt the message must be designed with a high degree of mathematical complexity, which cannot be reversed to obtain the plaintext from a known ciphertext. The length of the key used during encryption of a message plays an important role in deciding the effectiveness of an algorithm. Key length is conventionally measured in bits, and most of the well known strong ciphers have key lengths between 128 and 256 bits. A cipher is considered strong if, after years of attempts to find a weakness in the algorithm, there is no known effective cryptanalytic attack against it. This indicates that, the most efficient way of breaking an encrypted message without knowing the key used to encrypt it is to brute force it, i.e. trying all possible keys. The effort required to break an encrypted message is determined by the number of possible keys, known as thekeyspace. Knowing the speed of the computer to break the key, it is easy to calculate how long it would take to search the keyspace to break a particular cipher [2]. For example, considering a cipher that uses 128-bit keys, each bit can either be 0 or 1, so, there are 2128 or 3ÃÆ'-1038 keys approximately. Suppose we imagine that about ten billion computers are assigned the task of breaking the code, each capable of testing ten billion keys per second, then, the task of running through the entire keyspace would take around 3ÃÆ'-1018seconds, which is about 100 billion years. But, in fact, it would be necessary to run through only half the keyspace to hit upon the correct key, which would take around 50 billion years. This is longer than the estimated age of the universe according to modern cosmology, which is about 15 billion years [2]. This shows that, it is practically infeasible to crack modern cryptographic algorithms using Brute Force attacks. So, one can imagine the effectiveness of the modern cryptographic algorithms and their resistance towards cryptanalytic attacks. Conclusions: Cryptography has progressed in recent years and modern cryptographic algorithms have proved to be successful in defending against most forms of cryptanalytic attacks. Frequency analysis based attacks have proved to exploit the weaknesses in traditional encryption algorithms into revealing the plaintext message that was encrypted using them. The natural language used to encrypt messages is not considered to be random in nature, which is exploited by frequency counting based attacks. Based upon the frequency of letters that occur in the ciphertext, one can guess the plaintext characters due to their redundancy rate and the specific combination of letters in a word. This weakness can be repelled by using stream ciphers, which do not carry the redundancy in the plaintext to the ciphertext. Modern block cipher, encrypt a chunk of plaintext into ciphertext and vice versa, eliminating the redundancy of language used in encryption. Although the algorithm plays an important part, it is the key length used in block ciphers that helps in repelling cryptanalysis. Modern ciphers use a key length starting from 128 bits, eliminating the possibility of a brute force attack to decrypt the message. The higher the key length, the more time it takes to break these ciphers. These advantages have made modern cryptographic algorithms more popular among the security community. No known weaknesses have been found in these algorithms yet, that may allow one to identify the plaintext message. Bibliography: [1] Stallings, W., Cryptography and Network Security, Chapter 1, Third Edition, Prentice Hall, 2003 [2] Schneier, B., Applied Cryptography, Chapter 1, Second Edition, John Wiley Sons, New York City, New York, USA, 1996 [3] Hart, G.W., To Decode Short Cryptograms, Communications of the ACM 37(9), 1994, pp. 102-108 [4] Lee, K.W., Teh, C.E., Tan, Y.L., Decrypting English Text Using Enhanced Frequency Analysis, National Seminar on Science, Technology and Social Sciences (STSS 2006), Kuantan, Pahang, Malaysia [5] Zipf, GK., Human Behaviour and the Principle of Least Effort, 1949, Cambridge: Addison Wesley Publications. [6] Lewand, R.E., Cryptological Mathematics, The Mathematical Association of America, 2000, Pages 345-346 [7] Stamp, M and Low, R.M., Applied Cryptanalysis, 2007, Chapter 1 and 2, John Wiley Sons, New York City, New York, USA [8] http://www.simonsingh.net, Online internet frequency analysis tools [9] http://www.textalyser.net, online text analysis and frequency analysis information