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

Which authorization model could be ideal, Question: (a) Your office ad...

Question: (a) Your office administrator is being trained to take server backups. Which authorization model could be ideal for this situation: MAC, DAC or RBAC? Justify your a

Ethernet network, QUESTION : a) A datagram of 3000 bytes has to travel...

QUESTION : a) A datagram of 3000 bytes has to travel over a network with a MTU size of 1000 bytes. Describe how fragmentation can be used to solve this problem. You should pr

Fragmentation and path mtu, FRAGMENTATION AND PATH MTU IPv6 source is ...

FRAGMENTATION AND PATH MTU IPv6 source is responsible for fragmentation. Routers simply drop datagrams bigger than network MTU. So source have to fragment datagram to arrive d

Address resolution with message exchange, ADDRESS RESOLUTION WITH MESSAGE E...

ADDRESS RESOLUTION WITH MESSAGE EXCHANGE An alternative to local calculation is a distributed function. A computer that requires to find an address transmits a message across

Problem of spam mail, Topic -Spam is an ever-growing problem, with some net...

Topic -Spam is an ever-growing problem, with some network administrators reporting that 90% or moreof the email delivered to their mail servers is spam. Identify and briefly evalua

Advantages and disadvantage of packet filtering firewall, Advantages and Di...

Advantages and Disadvantage of Packet Filtering firewall   Advantages One screening router can help protect entire network One key advantage of packet filter

Internet protocol (ipv6), SUCCESS OF IP:  IP has accommodated dramatic...

SUCCESS OF IP:  IP has accommodated dramatic modification since real design. But basic rules are still appropriate today. There are many new kinds of hardware. SCALING:

Layering, ADDRESS RESOLUTION AND PROTOCOL ADDRESSES Address resolution...

ADDRESS RESOLUTION AND PROTOCOL ADDRESSES Address resolution (ARP) is a network interface layer protocol. Protocol addresses are used in all upper layers. Address resolution s

Explain the concept behind digital signature, Question: a) Differenti...

Question: a) Differentiate between ‘Gross Settlement' and ‘Multilateral Net Settlement' providing suitable examples where necessary to support your answer. b) Differentia

Find the possible deciphering transformations, Question: (a) A string o...

Question: (a) A string of ciphertext was enciphered using an a±ne transformation of single letters in a 28-letter alphabet consisting of A to Z, a blank and a?, where A to Z ha

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