User Account

All Pages

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

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

What is the size of the initialization vector n wpa, Question : Wi-Fi p...

Question : Wi-Fi protected access (WPA) was specified by the Wi-Fi alliance with the primary aim of enhancing the security of existing 802.11 networks. However, WPA was only a

Packet filtering firewall, Packet Filtering Firewall Packet filtering i...

Packet Filtering Firewall Packet filtering is a network security mechanism that works by controlling what data can flow in and out of the network. The basic device that interco

Example of an attack against a windows, The objective of this example is to...

The objective of this example is to demonstrate the steps required for a successful attack against a vulnerable Windows XP SP2 system. It will show: a) how Nessus can be used to di

Frame format and error detection, FRAME FORMAT AND ERROR DETECTION The...

FRAME FORMAT AND ERROR DETECTION The changed frame format also adds CRC. If there is an error happened in frame, then it typically causes receiver to removed frame. The frame

Access control matrix, You are provided with 3000 sample keystrokes for 5 u...

You are provided with 3000 sample keystrokes for 5 users mentioned above. You can find this data using the ‘Lab 2 User Data' link in the ‘Lab 2' folder on Blackboard. Please note t

What is internet, The Internet is known as the set of networks connect...

The Internet is known as the set of networks connected by routers that are configured to pass traffic among any machine attached to any network in the set. By internet several

Fragmentation, FRAGMENTATION One method is to limit datagram size to s...

FRAGMENTATION One method is to limit datagram size to smallest MTU of any server. IP needs fragmentation i.e. datagrams can be divided into pieces to fit in network with small

Audit or review of the information security issues, Using the selected appr...

Using the selected approach, you should then conduct an audit or review of the information security issues associated with the use of computing facility and report on the findings.

Elliptic curve encryption - decryption scheme, (a) (i) If m = p·q·r where...

(a) (i) If m = p·q·r where p, q, and r are prime numbers, what is Φ(m)? (ii) Therefore, Determine Φ(440). (b) Describe the following terms as used in cryptography: (i)

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

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!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

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