ciphertext, Computer Network Security

Assignment Help:
Encode the following plaintext, using the Caesar cipher:

LORD OF THE RINGS
b) The following ciphertext

jw njbh lxmn cx kanjt

has been encoded using a generalised Caesar cipher where the following rule computes a character ci in the cipher text from a character pi in the plain text:

ci = E(pi) = pi + d

where d is a positive integer.

Find the number d and the plain text. Hint: use a table of English letter frequencies. This information can be found on the Internet.

c) Now consider the following cipher text:

homlox prv hetorx orxolxpersorx

A more general substitution cipher has been used. Recall that this means that every letter of the alphabet appearing in the plain text is replaced with another unique letter of the alphabet. For example, the letter ''a'' could be mapped into ''h'', the letter ''b'' into ''x'' etc. The ciphertext then simply consists of these mapped letters.
Work out the original plain text message, using the following approach:

(i) Write a line of dashes ("_") as placeholders for the plaintext characters corresponding to each letter in the above cipher text. Make sure you also mark the spaces between the different words as they will give you clues as soon as you know some of the letters.

(ii) Using the English letter frequency table, find the letter which the letter "e" is most likely to be replaced with. Use this to replace some of the "_" by the letter "e" (simply copy the last line you wrote and then replace).

Related Discussions:- ciphertext

Structure of a typical frame relay, Problem a) Consider a 1000 Mbps Eth...

Problem a) Consider a 1000 Mbps Ethernet with a single Store-N-Forward switch mid-way in the path between two nodes A and B. Assume that there are no other nodes on the network

Looking for data network security assignment, I am ryan, i am looking for d...

I am ryan, i am looking for data security and network assignment help, Do you have experts in data security?

Explain how the key exchange algorithm works, Question: (a) Explain how...

Question: (a) Explain how the Diffie-Hellman key establishment protocol works. (b) Prove that the Diffie-Hellman key establishment protocol is vulnerable to a `man in the mi

What is information security, What is information security Information s...

What is information security Information security protects information (and facilities and systems which store, use and transmit it) from a broad range of threats, in order to p

Perimeter network security system, Title: Perimeter Network Security System...

Title: Perimeter Network Security System Outline Requirements The University is based in Glasgow, and provides higher education services to its students and staff. It is loc

Routers, Routers They transfer packets among multiple interconnected n...

Routers They transfer packets among multiple interconnected network machines (i.e. LANs of different kind). They perform in the data link, physical and network layers. They ha

Using Technology as Experience Framework, Write a two to three (2-3) page p...

Write a two to three (2-3) page paper in which you: Explain how the Web user interfaces help donors to make decisions. Relate the emotional thread demonstrated in the case study to

Explain the term quality of service in networks, QUESTION (a) One of th...

QUESTION (a) One of the biggest drawbacks that GNS3 has is that it supports only the IOS images of routers. This means that users cannot emulate Cisco switches. Suggest two sol

Explain authentication process in a synchronous token system, Question: ...

Question: (a) Explain briefly the PCI Control Objectives which enterprises must meet to be compliant with the Payment Card Industry Data Security Standard (PCI DSS). Specify a

Risk assessment, RISK ASSESSMENT Risk assessment is a step in a risk man...

RISK ASSESSMENT Risk assessment is a step in a risk management technique. Risk assessment is the determination of quantitative or qualitative value of risk related to a concrete

Write Your Message!

Captcha
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