Compute the relative frequencies of each letter in a cipher

Assignment Help Basic Computer Science
Reference no: EM13756631

Question

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.

The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, and still has modern application. As with all single alphabet substitution ciphers, the Caesar cipher is easily broken and in modern practice offers essentially no communication security. Generally speaking, it is a great exercise to understand crypto, and for our purposes, it deals with various concepts for learning a new programming language.

The Caesar Cipher, the Multiplication Cipher and the Linear Cipher have one property in common. They all fall in the category of Monoalphabetic Ciphers: "Same plain letters are encoded to the same cipher letter." I.e. in the Caesar Cipher each "a" turned into "d", each "b" turned into "e", etc.

The following holds true for each of the above Ciphers: Although letters are changed the underlying letter frequencies are not! If the plain letter "a" occurs 10 times its cipher letter will do so 10 times. Therefore, ANY Monoalphabetic Cipher can be broken with the aid of letter frequency analysis.

To compute the relative frequencies of each letter in a cipher text simply count the occurrences of the letter in the text. Afterwards compare the letter frequencies with those of the English language (assuming that the cipher text stems from an English plain text). Remember that

a) The most frequent letter of the English language is "e" (with about 12%) followed by t,i,o,a,n,s,r which is very helpful to break the cipher text.

b) The longer the cipher text the better do the counted letter frequencies converge to the actual English plain letter frequencies.

Reference no: EM13756631

Questions Cloud

Compare leadership teams and quality improvement teams : Compare leadership teams and quality improvement teams. Briefly describe the various elements of strategy development. List the practices used to improve customer-supplier relationships
Bounded rationality : Research, then define, “Bounded Rationality” and give an example of when it’s played a part in your life. This is a two-page paper minimum, APA format. The title page, references and abstract do NOT count to the total. I expect TWO FULL PAGES in the ..
Explain role capitalism plays in corporate decision-making : Explain the role capitalism plays in corporate decision-making- Discuss if you believe it is possible for a company to cater to both its best interest and that of the consumer conjointly or if one always has to prevail. Justify your response.
Reference price for the evolution series locomotive engine : In 2005 GE released its Evolution Series locomotive engine. Estimated fuel savings were roughly 1,000,000 gallons per year. At the time of its release, GE and other competitors were selling numerous locomotives priced near $2 million. What is the ref..
Compute the relative frequencies of each letter in a cipher : The most frequent letter of the English language is "e" (with about 12%) followed by t,i,o,a,n,s,r which is very helpful to break the cipher text.
Create a report explaining the research process : A company is considering creating and selling a new type of cookies. Create a report explaining the research process that should be used by the company to make this decision. What is the research question? How would you design the research project? W..
What are the inputs to and outputs of a supply chain : You are hosting a tailgate party for forty people prior to the next home game for your university football team. The menu includes burgers with all of the fixings, brats, and ribs. You are responsible for procuring all the ingredients and the transpo..
Explain an efas table for your selected company : Prepare and explain an EFAS table for your selected company. Data presented in tables do not speak for themselves. Whenever you present the results of data analysis, you must interpret the data. What does it indicate? What does it mean? What are t..
Create a report describing the process needed to manufacture : In a 4- to 5-page Microsoft Word document, create a report describing the process needed to manufacture your computer. Include the following in your explanation: The layout needed to manufacture the computer

Reviews

Write a Review

Basic Computer Science Questions & Answers

  Pipeline diagram for processor which has no forwarding

If the processor has no forwarding, how many cycles will one loop iteration take? show a pipeline diagram to support your answer.

  Round-robin scheduling is used to execute the processes

a) If round-robin scheduling is used to execute the processes, how many items will each process have produced and consumed at the end of 10 time quanta? Assume that the initial run queue order is P1, P2, P3, C1.

  Transform the query into a query on fragments

Transform the query into a query on fragments.

  In network cabling technology

In network cabling technology, what does the "100" in 100BaseT stand for?n network cabling technology, what does the "100" in 100BaseT stand for?

  Describe one real or future (even imaginary) iot

Describe one real or future (even imaginary) IoT (or CPS - Cyber Physical System) usecase. Provide details on the system(s) requirements from user(s)/actor(s) perspective.

  Representing information by predicate-calculus sentences

Represent this information by predicate-calculus sentences in such a way that you can represent the question Is there a member of the alpine club

  Analyze the use of gestures in ipads

Analyze the use of gestures in iPads. Address how users feel about gestures. Evaluate how users feel about the user input when it comes to filling out complicated forms on the iPad.

  What is the technique called

In the transport layer, data transmission is controlled to ensure data integrity and avoid data loss. What is the technique called?

  Describe the details of the working of any practical idps

Describe the details of the working of any practical IDPS (e.g. Snort, Tripwire). Include actual commands and screenshots. Include references and proper citations.

  Application of artificial intelligence in different fields

What are application of artificial intelligence in different fields and also explain it and what are application of artificial intelligence in computer science give an example?

  Aspects of negotiation will point out it is proceeding well

What aspects of negotiation will point out it is proceeding well or poorly? What will tell you that it is time to arrange further meeting? What signs will you utilize to decide when change in negotiators is necessary?

  Flowchart a program by using ms viso

Flowchart a program by MS Viso, using conventions presented in the text, that will prompt user to input a name and the number of credit hours taken towards their degree.

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd