Blowfish Algorithm Advantages and Disadvantages

Blowfish Algorithm Advantages and Disadvantages Blowfish is a keyed (piece of information that determines the functional output of a cryptographic algorithm or cipher), symmetric cryptographic block cipher. It was designed by Bruce Schneier in 1993. Since then it has been analyzed considerably, and it is slowly gaining acceptance as a strong encryption algorithm. Blowfish is license-free and is available free for all uses. It is also a symmetric block cipher that can be used as a drop-in replacement for DES or IDEA. It takes a variable-length key, from 32 bits to 448 bits, making it ideal for both domestic and exportable use. Blowfish is also one of the fastest block ciphers in public use, making it ideal for a product that functions on a wide variety of processors found in mobile phones as well as in notebook and desktop computers. The first implementation of the Blowfish Algorithm in LabVIEW. With this set of subvis one can encrypt data in LabVIEW without the need of external software. This can be used to send data securely over Data socket as well as TCP and UDP communications along with protect remote control systems from unauthorized access, by encrypting the control communications. .( B. Schneier, Applied Cryptography, John Wiley Sons, New York, 1994.) 3.2 Strategies and Mechanisms Blowfish has a 64-bit block size and a key length of somewhere from 32 bits to 448 bits. The algorithm consists of two parts. One is a key-expansion part and one more is a data- encryption part. Key expansion converts a key of at most 448 bits into several subkey arrays totaling 4168 bytes. It is a 16-round Feistel cipher and uses large key-dependent S-boxes (basic component of symmetric key algorithms which performs substitution). Each round consists of a keydependent permutation, and a keydependent substitution. It is also similar in structure to CAST-128, which uses fixed S-boxes. Blowfish is suitable for application where the key does not change frequently, like a communication link or an automatic file encryptor. It is significantly faster than most encryption algorithm when on 32-bit microprocessor with large data caches. (Fast Software Encryption, Cambridge Security Workshop Proceedings December 1993) 3.3 The Feistel structure of Blowfish A Fiestel network is a general method of transforming any function (generally called F- function) into a permutation. It was inented by Horst Fiestel and has been used in many block chiper designed. The diagram below shows the action of Blowfish. Each line represents 32 bits. The algorithm keeps two subkey arrays: the 18-entry P-array and four 256-entry S-boxes. The S-boxes accept 8-bit input and produce 32-bit output. One entry of the P-array is used every round, and after the final round, each half of the data block is XORed with one of the two remaining unused P-entries. The diagram to the right shows Blowfishs F-function. The function splits the 32-bit input into four eight-bit quarters, and uses the quarters as input to the S-boxes. The outputs are added modulo 232 and XORed to produce the final 32-bit output. Since Blowfish is a Feistel network, it can be inverted simply by XO7Ring P17 and P18 to the cipher text block, then using the P-entries in reverse order. Blowfishs algorithm initialize with the P-array and S-boxes. The secret key is then XORed with the P-entries in order and then use the same method to encrypt all the zero string. The consequential ciphertext replaces P1 and P2 then encrypt the new P1 and P2 with the modified subkeys. Now the output is P3 and P4. Altogether Blowfish algorithm will repeat 521 times in order to calculate new subkeys for the P-array and the four S-boxes. It is about 4KB data is processed. The blowfish uses a large number of subkeys. These keys must be precomputed before any data encryption or decryption. The P-array consists of 18 32-bit subkeys: P1, P2, P3, P18. There are four 32-bit S-boxes with 256 entries each: S1,0, S1,1,, S1,255; S2,0, S2,1,..,, S2,255; S3,0, S3,1,, S3,255; S4,0, S4,1,..,, S4,255. Figure 3: Feistel Network (John Wiley Sons, New York, 1994) As what mentioned above, blowfish has 16 rounds. The method of calculating it: The input is a 64-bit data element, x. Divide x into two 32-bit half: xL, xR. Then, for i = 1 to 16: xL = xL XOR Pi xR = F(xL) XOR xR Swap xL and xR After the sixteenth round, swap xL and xR again to undo the last swap. Then, xR = xR XOR P17 and xL = xL XOR P18. Finally, recombine xL and xR to get the ciphertext. 3.4 Key Expansion Key expansion converts a key of at most 448 bits into several subkey arrays totaling 4168 bytes. The figure and the explanation of the Key Explanation of Blowfish are showed below Explanation for the Key Explanation of Blowfish figure : Step 1: Expand key to 576-bit XOR with P array Store results of 2 in P array Step 2: datal = 0x00000000; datar = 0x00000000; for (i = 0; i Blowfish_encipher(datal, datar); bf_P[i] = datal; bf_P[i + 1] = datar; } for (i = 0; i for (j = 0; j Blowfish_encipher(datal, datar); bf_S[i][j] = datal; bf_S[i][j + 1] = datar; } } 3.5 Application That Use Blowfish Method Below are the applications that using Blowfish Encryption: AEdit : A free Windows word processor incorporating text encryption. Coolfish: An encrypting text editor for Windows. Foopchat: Encrypted chat and advanced file sharing using a client/server architecture. JFile by Land-J Technologies: A database program for the PalmOS platform. Freedom by Zero-Knowledge: Privacy for web browsing, e-mail, chat, telnet, and newsgroups. JFile is one of the famous application that use blowfish method. JFile5 is the new version of the JFile. It is a flat-file database application for the PalmOS. There are 4 primary views in JFile 5.0. First is Main View, where it is the view that shows a list of all the JFile 5 databases that are currently installed on the Palm device. Second is New/Modify Database Structure View, this is the view when we are creating a new database, or modifying the structure of an existing database. Here is where we have to set the field names, the field types, the database name, and other elements of the database structure. The third view is Database View, this is the view that presented along when we tap on a database name from the Main View. The last view is Record View, this is the view that received when we tap a specific record from the Database View. In this JFile5 we can change the current method of security for each database by tapping the lock icon of the database on the main screen. There are three levels of security for databases in JFile5. The first level is the green/open lock where at this level the database contains no security, any user accessing the device can view and edit the database. The second level is the orange/grey closed lock, at this level the database is protected by the Security applications password (if it is set). To access this database, we will need to provide the password set in the Security application. This security level is appropriate for handing the Palm temporarily to a colleague so they wont have easy access to the database, but the information is not encrypted in any way. The third level is the red/dark closed lock at this level we will choose an encryption password for the database. The entire database will be encrypted, and we MUST remember the password to access the database. Due to the encryption, certain operations within the database will be slower. In addition, we will need to insure that any PC/Mac side utilities that we use w ith JFile support the encryption method. There are also some new features in this JFile5 where the maximum number of databases increased to 120 and it is improved use of color in the application compared to JFile4. There are 5 different sorts and filter settings can be saved for quick and easy usage, it is also easier to use because of the updated user interface. It is also has multiple locked columns for left/right scrolling in the main database view and the encryption of databases using 64-bit Blowfish algorithm. The VFS memory cards made easy movement of databases and have new calculated value field types. There are also default values for fields, read-only field options are also available with the Beam-Via-Coola (www.coola.com) support. They also enhanced resolution for Handera 330 devices, extensive keyboard input support and the Navigation of most common areas of JFile for JogDial equipped devices. The limitations for this JFile5 are 120 databases (1 in the demonstration version), 20 character maximum for field names, 50 fields maximum per databases, 4,000 characters per field of data, 10,000 characters per record of data and 16,000 records per database. 3.6 Hardware Architecture Pipelining is a famous technique for improving the throughput of computers, by using parallel elements so that several instructions can be worked on simultaneously. The basic idea of pipelining is to begin carrying out a new instruction before execution of an old one is completed. When pipelining is used, the number of steps in the basic algorithm is less important than fitting the steps into a framework so that they can be performed in parallel. The figure of the pippelining implementation are showed below These are processed separately (with delayed arithmetic carries shown in the figure as carry) and then combined at the end of processing. Even though more clock cycles are needed, the speed of the clock can be greatly improved, because smaller adders are required at each stage, with smaller internal propagation delays. (Malaysian Journal of Computer Science, Vol. 14 No. 1, June 2001, pp. 16-27) These are some examples of blowfish hardware architecture Figure 18: Chip Specifications What is this table? Explanation needed Mode Specification 0 Idle 1 Initial 2 Encrypt 3 DecryptTable 1: Mode Specification What is this figure? Explanation needed The controller is implemented as a Finite State Machine and described in a behavioral Verilog model. The figure and the explanation of the Finite State Machine are showed below Figure 20: FSM of Controller (Bruce Schneier, Applied Cryptography, John Wiley Sons, Inc. 1996) Explanation of Finite State Machine figure : e1: Finish loading data from ROM to SRAM e2: Finish initialization and mode != 1 e3: Finish encryption and mode != 2 e4: Finish decryption and mode != 3 Datapath includes ROM modules, SRAM modules, and the main arithmetic units of Blowfish. The figure showed below is the architecture of the datapath Figure 21 : The architecture of the datapath Explanation for the figure of the architecture : The  Ã‚ ° string is mapped to ROM_P and ROM_S-box. The P-array is mapped to SRAM_P, and the four S-boxes are mapped to SRAM_Sbox. Because the size of SRAM module is 2n words, P1 and P18 are implemented as registers, and the others are mapped to 1632 bits SRAM. We use a shift register under DataIn to expand 4-bit input to 64-bit input and a shift register over DataOut to reduce 64-bit output to 4-bit output. CORE implements the loop of the 16-round iteration. A pipeline stage is added to the output of the SRAM modules. The pipeline stages will double the performance of the Blowfish hardware but lead to the overhead of area. 3.7 Advantages and Drawbacks Blowfish is one of the fastest block ciphers in general use, except when changing keys. Each new key requires pre-processing equivalent to encrypting about 4 kilobytes of text, which is very slow compared to other block ciphers. This prevents its use in certain applications, but is not a problem in others, such as SplashID. In an application, its actually a benefit especially the password-hashing method used in OpenBSD uses an algorithm derived from Blowfish that makes use of the slow key schedule. Blowfish is not subject to any patents and is therefore freely available for anyone to use. This has contributed to its popularity in cryptographic software. The disadvantages of Blowfish are it must get key to the person out of band specifically not through the unsecured transmission channel. Each pair of users needs a unique, so as number of users increase, key management becomes complicated. For example N(N-1)/2 keys required. Blowfish cant provide authentication and non-repudiation as two people have same key. It also has weakness in decryption process over other algorithms in terms of time consumption and serially in throughput

New England: A Matter Of Perspective Essay -- essays research papers

New England: A Matter of Perspective   Ã‚  Ã‚  Ã‚  Ã‚  John Smith's A Description of New England and William Bradford's Of Plymouth Plantation both present a picture of the same pre-colonial land of New England. Mr. Smith's writing, out of necessity, painted a rosy picture of the new land, while Bradford's historical account shows early New England was not Heaven on Earth. Mr. Bradford and Mr. Smith are writing about one land, but they present two different accounts of the life in the land.   Ã‚  Ã‚  Ã‚  Ã‚  John Smith's writing is his ideal vision of what the new land could be with the best of people colonizing the new land. John Smith's fine piece of literature may also be considered a beautifully worded, finely tuned piece of propaganda. Mr. Smith wrote this selection to influence people to leave their lives in England and cross the globe to start a new life in a strange land. John Smith described a a land where little work was needed, and riches could be easily acquired. A man with little fishing ability could catch one hundred, two hundred, or three hundred fish a day. He tells of animals perfect for hunting that give plenty of food to live on, and rich furs that could be traded for money. Mr. Smith declares the land free, so anyone could come to the New World and accumulate great wealth. John Smith envisioned a land where all men would live in peace and harmony, a vision that would not be fulfilled in New England or any of the New World.  ...

Mind and Rumors Essay

Rumors are dark, hurtful, mischievous things that are spread to cause destruction. Rumors have been around since the beginning of time, and are stronger now more than ever. Rumors are whispered, as if to indicate that they will not spread. Rumors are shouted, printed, posted, and broadcasted. Rumors are lies and those whom associate with rumors are bad people, or are they? Rumors are not always bad, and they don’t always turn out to be lies. There are many unknown things about rumors, like how and why are they really created? DiFonzo defines a rumor as â€Å"†¦unverified information statements that circulate about topics that people perceive as important; arise in situations of ambiguity, threat, or potential threat; and are used by people attempting to make sense or to manage risk† (375). A rumor starts out as an important thought in one persons mind. A thought that is kept to oneself merely stays a thought and never develops into a rumor. But, a thought that is just important enough to share with someone else morphs into a rumor. Rumors are not always intentional lies. They do however start out as unverified information. If a rumor is verified it is no longer a rumor, it then becomes factual information. The information that is passed from one person to many people is thought to be of importance. Whether the rumor pertains to something local, nationwide, global, social, political, public, or private it contains information that is substantial and has the possibility to be life changing. A rumor is targeted to a certain group of people. The spread of the rumor depends on the number of people who perceive the information as important. The group can range from a few people to the majority of the world. A rumor of â€Å"Bob cheated on Mary with Susan† would certainly be very important to a small number of people and could devastate their lives. On the other side of the spectrum a rumor that â€Å"An asteroid five times the size of Saturn is headed toward earth and total death is imminent† would also be of great importance and would affect many people. Rumors are born, bred, and sought out of human emotion. The amount of rumors increase in times of perceived danger, threat, and stress. â€Å"In practice it has been found that the emotional needs most frequently served by rumors are wish, fear, and hostility† (Knapp 361). A rumor is spread or sought to satisfy an emotional need of hope, comfort, fear, and hostility. Therefore it makes sense that the amount of rumors increases during stressful times. In the aftermath of the recent tornados in Oklahoma, rumors exploded. Social media, radio stations, and television stations broadcast the information from the moment of touchdown. Two different television stations broadcast contradicting information at the same time and facebook erupted with photos, videos, and information. People were calling other people, turning on the television, and getting on facebook to seek information or give it. They sought answers, comfort, and hope. Why then do some rumors flourish and are known all over the world and others die out after only a short run? One reason has already been brought up, the number of people who consider the information important. A rumor can live longer if it is adaptable to its audience. A rumor that has information added to or taken out may appear more important to certain groups. Another factor in a successful rumor is the length of it. A rumor that is long and complicated will be hard to remember and hard to tell. Another reason is the desire for humans to be accepted. People will agree with someone else even if they are not sure themselves to avoid hostility and risk losing other peoples good opinion of them. Perhaps people agree because of self-doubt. If one person thinks a rumor is wrong but is hesitant to disagree because the majority believe it to be true then they must be wrong and not the group. People’s personal and social anxiety can escalate a rumor fast and wide. If the majority of people are passive, have self-doubt, or want to avoid conflict then the number of people who perceive the rumor to be true increases. Sunstein states, â€Å"Often people will be suspicious of a rumor, or believe that it is not true, but they will not contradict the judgment of the relevant group, largely in order to avoid social sanctions† (393-394). In conclusion, it is sufficient to say that rumors are more complex than originally thought. They have distinct characteristics and classifications that define them. The most successful rumors are important to the world. If a rumor is assembled just right under the perfect conditions, the result are everlasting.

Cosmos Episode 12 Viewing Worksheet

Cosmos Episode 12 Viewing Worksheet In the spring of 2014, Fox aired the television series Cosmos: A Spacetime Odyssey hosted by Neil deGrasse Tyson. This amazing show, with solid science explained in a totally accessible way, is a rare find for a teacher. Not only is it informative, but students also seem to be entertained and invested in the episodes as Neil deGrasse Tyson narrates and gets excited. Whether,  as a teacher, you  need a video to show your  class as a reward or as a supplement to a science topic, or even as a lesson plan to be followed by a substitute, Cosmos has you covered. One way you can assess the students learning (or at the very least to keep them focused on the show) is to give them a worksheet to fill out during the viewing, or as a quiz afterward. Feel free to copy and paste the worksheet below and use it as the students watch Episode 12 of Cosmos entitled The World Set Free. This particular episode is also a great way to battle any resistance to the idea of global climate change. Cosmos Episode 12 Worksheet Name:______________ Directions: Answer the questions as you watch episode 12 of Cosmos: A Spacetime Odyssey What planet is Neil deGrasse Tyson talking about when he says it used to be paradise?How hot is the surface of Venus?What are the clouds that block the Sun on Venus made of?Which country landed a probe on Venus in 1982?What is the difference in the way carbon is stored on Venus and on Earth?What living thing created the White Cliffs of Dover?What would Venus have needed in order to store carbon in the form of a mineral?What on Earth primarily controls the amount of carbon dioxide in the air?What did Charles David Keeling manage to do in 1958?How can scientists read the â€Å"diary† of the Earth written in the snow?What major event in history is the starting point of the exponential rise of carbon dioxide in the atmosphere?How much carbon dioxide do volcanoes add to the atmosphere on Earth every year?How did scientists conclude the extra carbon dioxide in the air contributing to climate change was not made from volcanoes, but instead comes from burning fossil fuels?How much ext ra carbon dioxide are humans putting into the atmosphere every year by burning fossil fuels? How much additional carbon dioxide has been spewed into the atmosphere since Carl Sagan first warned about doing so in the original â€Å"Cosmos† television series in 1980?What do Neil deGrasse Tyson and his dog walking on the beach symbolize?How are the polar ice caps an example of a positive feedback loop?At what rate are the Arctic Ocean ice caps receding now?How is the permafrost near the North Pole melting increasing carbon dioxide levels?What are two ways we know that the Sun is not the cause of the current global warming trend?What amazing invention did Augustin Mouchot first display in France in 1878?Why was there no interest in Augustin Mouchot’s invention after he won the gold medal at the fair?Why did Frank Shuman’s dream of irrigating the desert in Egypt never come to be?How much of the wind’s power would have to be tapped in order to run all of civilization?The manned missions to the moon were a direct result of what period in the United State s’ history?Who were the first group of people to stop wandering and begin civilization by using agriculture?

Independent and Dependent Variable Examples

Independent and Dependent Variable Examples The independent variable and dependent variable are examined in an experiment using the scientific method, so its important to know what they are and how to use them. Here are the definitions for independent and dependent variables, examples of each variable, and the explanation for how to graph them. Independent Variable The independent variable is the condition that you change in an experiment. It is the variable you control. It is called independent because its value does not depend on and is not affected by the state of any other variable in the experiment. Sometimes you may hear this variable called the controlled variable because it is the one that is changed. Do not confuse it with a control variable, which is a variable that is purposely held constant so that it cant affect the outcome of the experiment. Dependent Variable The dependent variable is the condition that you measure in an experiment. You are assessing how it responds to a change in the independent variable, so you can think of it as depending on the independent variable. Sometimes the dependent variable is called the responding variable. Independent and Dependent Variable Examples In a study to determine whether how long a student sleeps affects test scores, the independent variable is the length of time spent sleeping while the dependent variable is the test score.You want to compare brands of paper towels, to see which holds the most liquid. The independent variable in your experiment would be the brand of paper towel. The dependent variable would be the amount of liquid absorbed by a paper towel.In an experiment to determine how far people can see into the infrared part of the spectrum, the wavelength of light is the independent variable and whether the light is observed (the response) is the dependent variable.If you want to know whether caffeine affects your appetite, the presence/absence of the amount of caffeine would be the independent variable. How hungry you are would be the dependent variable.You want to determine whether a chemical is essential for rat nutrition, so you design an experiment. The presence/absence of the chemical is the independent v ariable. The health of the rat (whether it lives and can reproduce) is the dependent variable. If you determine the substance is necessary for proper nutrition, a follow-up experiment would be to determine how much of the chemical is needed. Here, the amount of chemical would be the independent variable and the rat health would be the dependent variable. How to Tell the Independent and Dependent Variable Apart If you are having a hard time identifying which variable is the independent variable and which is the dependent variable, remember the dependent variable is the one affected by a change in the independent variable. If you write out the variables in a sentence that shows cause and effect, the independent variable causes the effect on the dependent variable. If you have the variables in the wrong order, the sentence wont make sense. Independent variable causes an effect on the dependent variable. Example: How long you sleep (independent variable) affects your test score (dependent variable). This makes sense, but: Example: Your test score affects how long you sleep. This doesnt really make sense (unless you cant sleep because you are worried you failed a test, but that would be a whole other experiment). How to Plot Variables on a Graph There is a standard method for graphing the independent and dependent variable. The x-axis is the independent variable, while the y-axis is the dependent variable. You can use the DRY MIX acronym to help remember how to graph variables: DRY MIX DÂ   dependent variableRÂ   responding variableYÂ   graph on the vertical or y-axis MÂ   manipulated variableIÂ   independent variableXÂ   graph on the horizontal or x-axis Test your understanding with the scientific method quiz.

Police Discretion in Domestic Violence Research Paper

Police Discretion in Domestic Violence - Research Paper Example Most police officers feel that a domestic dispute is a private matter that should be handled by both parties. However, police officers mostly rely on their experience as police officers to handle the situation as they think appropriate. Police Discretion in Domestic Violence Introduction Family problems which breed domestic violence are universal issues which affect all members of the family including parents and children. Domestic violence can be fatal, but it can be effectively controlled with the proper implementation of law and timely and appropriate intervention by the police. Police reactions to incidents of domestic violence have usually depended upon the attitude and discretion of the officer involved in investigating the reported incident. â€Å"Discretion can be characterized as the authority of the police officer to chose his/her course of action or inaction. Police have discretionary powers in their positions as protectors of the public and upholders of the law. A lot ha s been written about police discretion in the criminal justice field procedures. It has been proved that arrests in such matters reduce incidences, as the offender might not repeat the offence for fear of prosecution. Many abused women do not call the police because they feel that they will not be taken seriously, and the police might make use of its discretionary powers and not arrest the abuser. In such cases, it leads to further violence causing greater injury or harm to the spouse, partner or children. Sometimes women do not report domestic violence because they do not want their spouse or partner to be arrested and sent to prison (Green & Kelso, 2010). Discussed below are some of pros and cons of the police discretion in domestic violence. Police discretion was an unmentionable subject right up to 1956, when it was brought to light by an American Bar Foundation Study. Until then, no one would admit that it was a reality. The approach of police high-ups was that any digression f rom accepted or written down procedures was not permissible by law, and most probably a basis for dishonesty. When it became public knowledge, the police administration made efforts to play it down or even have it outlawed. The actual problem lies in the abuse of discretion, not in its implementation. Police discretion is now accepted as an indispensable malevolence, which can be of great use if used properly. Community policing is where officers can exercise discretion to help the community more effectively. Discretion is good when it is managed and well thought-out. (Green & Kelso, 2010) Defining Police Discretion Some facts which can be regarded as both pros and cons depending upon application have described â€Å"police discretion† as an area where the law is not implemented or as the â€Å"gap in the doughnut†. Discretion is the vacant space which is surrounded by the relevant set of principles and procedures. Alternatively, it can be described as cases where no r ules are applicable and the officer makes a personal decision based on beliefs, assumptions and his own interpretation of the situation. Discretion is not the same as repetitive and consistent compliance. It entails information, talent and the ability to act and perform in random and awkward situations. Police are not soldiers who must obey orders blindly and without question. Police must be quite

Managing Operations Essay Example | Topics and Well Written Essays - 750 words

Managing Operations - Essay Example The paper will therefore analyze the production strategy the managers should choose based on the total cost minimization objective as well as summarizing the information about the aggregate plan to be shared with the supply chain partners. Production strategy based on the Total Cost Minimization The total cost minimization normally occurs at appoint when the marginal cost (MC) curve cuts the average total cost (ATC) curve at its minimum point. This therefore means that, at the minimum point, marginal cost (MC) should be equals to the Average Cost (AC). In most cases, the decision problems are usually molded as being a cost-minimization problem, and therefore, in every network, models usually have a minimization objective. The reasoning behind this is that, in particular, the decision situations never influences the income, hence minimizing costs will increase the opportunities of maximizing the profit (Shim & Siegel, 2002). The production manager should choose on pricing-based as a p roduction strategy to help in making decision based on the total cost minimization. When managers use price-based strategy, the products are usually planned according to cost-plus pricing, value-based pricing as well as target-return pricing. All these are set in such a way that the new product in the market has a competitive advantage over other similar products. Therefore, when there is no overtime for employees, managers have to make sure that the time spent by those employees is compensated for as opposed to when they work on normal hours (Media, 2010). Aggregate Plan The aggregate forecasts of the tank loads for several flavors should be shared to various supply chain partners. The forecast contains the intended tank load production every month from May through September. The company’s production capacity every month is also very important information for the suppliers. The company’s maximum tank loads production in a particular month is 60 tank loads, in May the forecast is 50 tank loads, in June it is 60, in July 70, in August 90, September 80 and finally October 70.There are several months where the forecasted production in a month exceeds the company’s ability these are the months of July, August September and October. Therefore this information on the extra tank loads that the company needs is very crucial supply chain partners. This is because from the information they will get to know of any extra tank loads that the company might require in a particular month and therefore their services might be required. This will give them a chance to offer the company their services in terms of producing the extra tank loads that they have forecasted and yet they are not in a position as a company to produce (Shim & Siegel, 2002). The other Very important information that the supply chains need is the amount of money that is set aside by the company as cost of subcontracting as well as overtime production by various supply chains. Subcontr acting and over production by the suppliers who are available is $1600 and $1800 per tank load. Therefore with this information any supply chain that intends to supply the extra trainloads can be in a position to set a price for their tank loads. They will ensure that they come up with prices that will give them a chance to be chosen as the preferred supplier for the extra tank loads. They also need to know the cost of holding tank loads in a month as well as backordering if made by the company. This will help them make a