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Friday, December 31, 2010

IT430 Assignment # 2 Solution

What are the steps involved in symmetric cryptography? Also explain key management in conventional cryptography using some example.
Solution:-
Symmetric Cryptography
With symmetric cryptography, both the sender and recipient share a key that is used to perform both encryption and decryption. Symmetric cryptography is commonly used to perform encryption. It also provides data integrity when symmetric keys are used in conjunction with other algorithms to create Message Authentication Codes (MACs). For more information about MACs, see Data Origin Authentication in Chapter 2, "Message Protection Patterns."
Figure 1 illustrates the process of encrypting and decrypting data with a shared secret key.



Figure 1. The process of symmetric encryption

As illustrated in Figure 1,
symmetric encryption involves the following steps:
The sender creates a ciphertext message by encrypting the plaintext message with a symmetric encryption algorithm and a shared key.
The sender sends the ciphertext message to the recipient.
The recipient decrypts the ciphertext message back into plaintext with a shared key.

Numerous symmetric algorithms are currently in use. Some of the more common algorithms include Rijndael (AES) and Triple DES (3DES). These algorithms are designed to perform efficiently on common hardware architectures.

Symmetric cryptography is comparatively simple in nature, because the secret key that is used for both encryption and decryption is shared between the sender and the recipient. However, before communication can occur, the sender and the recipient must exchange a shared secret key. In some cases (such as SSL), asymmetric cryptography can be used to ensure that the initial key exchange occurs over a secure channel.


Key Management and Conventional Encryption
Conventional encryption has benefits. It is very fast. It is especially useful for encrypting data that is not going anywhere. However, conventional encryption alone as a means for transmitting secure data can be quite expensive simply due to the difficulty of secure key distribution. The expense of secure channels and key distribution relegated its use only to those who could afford it, such as governments and large banks (or small children with secret decoder rings).

Recall a character from your favorite spy movie: the person with a locked briefcase handcuffed to his or her wrist. What is in the briefcase, anyway? It's probably not the missile launch code/ biotoxin formula/ invasion plan itself. It's the key that will decrypt the secret data.

For a sender and recipient to communicate securely using conventional encryption, they must agree upon a key and keep it secret between themselves. If they are in different physical locations, they must trust a courier, the Bat Phone, or some other secure communication medium to prevent the disclosure of the secret key during transmission. Anyone who overhears or intercepts the key in transit can later read, modify, and forge all information encrypted or authenticated with that key. The persistent problem with conventional encryption is key distribution: how do you get the key to the recipient without someone intercepting it?

And the minor problem with it is the storage of keys: when you want to communicate with a lot of people and you have one key for each partner, how do you manage so many keys?




Some Examples of Conventional Cryptosystems

Captain Midnight's Secret Decoder Ring (which you may have owned when you were a kid)

Julius Caesar's cipher

DES, Data Encryption Standard

ENG301(Business Communication) - Assignment 3 (Fall 2010)

Business Communication-ENG301 Total Marks: 15



Objective
To assess the students' ability to write business messages.

Instructions:

No assignment will be accepted via e-mail after the due date.

Plagiarism will NOT be tolerated. Plagiarism occurs when a student uses work done by someone else without acknowledging the actual author. It also means copying and pasting the material from handouts and internet source without rephrasing it in his/her own words.

Q1. As a reservation manager of a hotel, write a letter to your customer reminding him that deposit is due on a reservation made for an executive suite. (10)

Q2. Complete the following statements with the correct answers related to Business Communication. (5)

1. ----------- is the reply to a claim letter.

2. Letters written to persuade the people for purchasing your product are called -----.

3. -------- is a special committee which is assigned the duty to resolve a specific problem.

4. A sales letter begins with --------------.

5. ------------ of an organization is followed in order to write a ------------.


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Example
"Your company logo here"


Thursday, December 30, 2010

Dear Customer,

Please note that on your account, there are one or more invoices currently past the 30-day due date from the date of service. These invoices are itemized below for your convenience. Please remit the past due balance of $ 0,000.00 as soon as you are able, or contact our office if you have any questions regarding these. Please keep in mind that all invoices on your account carry 30-day terms unless otherwise specified.

Invoice Number Service Date Amount Due Total

87561 04/25/2005 $ 1,393.07

87591 04/27/2005 $ 170.84 $1,563.91


We appreciate your efforts in bringing the account current.

Your business is very important to us!

Thank you,


Name

Title, company name

Thursday, December 30, 2010

MKT624 Assignment 02 Announced

Semester “Fall 2010”

“Brand Management (MKT624)”

This is to inform that next Assignment (covering video lecture no. 1 to lecture no 27)

will be uploaded on VULMS according to the following schedule

Schedule

Opening Date and Time

December 31, 2010 At 12:01 A.M. (Mid-Night)

Closing Date and Time

January 04 , 2010 At 11:59 P.M. (Mid-Night)

Note: Only in the case of Assignment, 24 Hrs extra / grace period after the above mentioned due date is usually available to overcome uploading difficulties which may be faced by the students on last date. This extra time should only be used to meet the emergencies and above mentioned due dates should always be treated as final to avoid any inconvenience.

MGT201 GDB Announced

Semester “Fall 2010”

“Financial Management (MGT201)”

This is to inform that Graded Discussion Board (GDB)

has opened according to the following schedule

Schedule

Opening Date and Time

January 03, 2011 At 12:01 A.M. (Mid-Night)

Closing Date and Time

January 05, 2011 At 11:59 P.M. (Mid-Night)

Note: No extra or bonus/grace period is available for attempting GBD.

Topic/Area for Discussion

Capital Asset Pricing Model (CAPM)

Note: The discussion question will be from the area/topic mentioned above. So start learning about the topic now.

Wednesday, December 29, 2010

HRM627 Online Latest Quiz


Quiz Start Time: 01:07 PM

Time Left 80

sec(s)

Question # 1 of 15 ( Start time: 01:07:27 PM ) Total Marks: 1

Which of the following revolves primarily around the private sector controlling industry?

Select correct option:

Secularism

Capitalism

Socialist

Liberalism

Quiz Start Time: 01:07 PM

Time Left 79

sec(s)

Question # 2 of 15 ( Start time: 01:08:27 PM ) Total Marks: 1

Gestures, facial expression and body movements are all part of:

Select correct option:

Facilitation

Encoding

Posturing

Nonverbal communication

Quiz Start Time: 01:07 PM

Time Left 87

sec(s)

Question # 3 of 15 ( Start time: 01:09:00 PM ) Total Marks: 1

The power exercised by the surgeon is an example of ___________.

Select correct option:

Referent power

Expert power

Legitimate power

Coercive power

Quiz Start Time: 01:07 PM

Time Left 87

sec(s)

Question # 4 of 15 ( Start time: 01:09:27 PM ) Total Marks: 1

In Gini coefficient, 1 corresponds to ________________.

Select correct option:

Inequality

Perfect inequality

Equality

Perfect equality

Quiz Start Time: 01:07 PM

Time Left 69

sec(s)

Question # 5 of 15 ( Start time: 01:10:49 PM ) Total Marks: 1

The National Education Policy 1998 has included many elements and strategies for improving quality at____________.

Select correct option:

Higher level

Tertiary level

Elementary level

Adult Level

Quiz Start Time: 01:07 PM

Time Left 87

sec(s)

Question # 6 of 15 ( Start time: 01:11:48 PM ) Total Marks: 1

___________ can have good effect on our mental state.

Select correct option:

Positive words

Toxic words

Caustic words

Negative words

Quiz Start Time: 01:07 PM

Time Left 79

sec(s)

Question # 7 of 15 ( Start time: 01:12:15 PM ) Total Marks: 1

The HDI measures the average achievements in a country in all the basic dimensions of human development EXCEPT:

Select correct option:

Long and healthy life

Culture

Knowledge

Standard of living

Quiz Start Time: 01:07 PM

Time Left 73

sec(s)

Question # 8 of 15 ( Start time: 01:13:46 PM ) Total Marks: 1

Degree to which people like or dislike themselves is:

Select correct option:

Self-esteem

Self-monitoring

Locus of control

Stereotyping

Quiz Start Time: 01:07 PM

Time Left 88

sec(s)

Question # 9 of 15 ( Start time: 01:14:23 PM ) Total Marks: 1

In Pakistan, about how many schools are located in rural areas?

Select correct option:

30%

85%

71%

60%

Quiz Start Time: 01:07 PM

Time Left 88

sec(s)

Question # 10 of 15 ( Start time: 01:15:12 PM ) Total Marks: 1

Which country tops the list of South Asian countries in terms of the Human development Index?

Select correct option:

Africa

Bangladesh

Sri Lanka

India

Quiz Start Time: 01:07 PM

Time Left 87

sec(s)

Question # 11 of 15 ( Start time: 01:16:21 PM ) Total Marks: 1

Which type of development is required in bringing order, discipline and peace into life?

Select correct option:

Ethical and democratic

Financial and economic

Moral and spiritual

Nutritional

Quiz Start Time: 01:07 PM

Time Left 88

sec(s)

Question # 12 of 15 ( Start time: 01:17:30 PM ) Total Marks: 1

The component of an attitude that refers to an intention to behave in a certain way toward someone or something is called:

Select correct option:

Affective component

Environmental component

Cognitive component

Behavioral component

Quiz Start Time: 01:07 PM

Time Left 83

sec(s)

Question # 13 of 15 (Start time: 01:18:20 PM ) Total Marks: 1

Which type of managers take less time to make their decisions and less information in making their choices?

Select correct option:

Rational mangers

Low risk taking managers

Efficient managers

High risk taking managers

Quiz Start Time: 01:07 PM

Time Left 88

sec(s)

Question # 14 of 15 (Start time: 01:18:43 PM ) Total Marks: 1

When we show interest, understanding and fun, we are in which following state?

Select correct option:

Parent ego state

Adapted child ego state

Adult ego state

Natural child ego state

MGT602 Quiz 03 Announced

On-Line Quiz (No.03) Announcement

Entrepreneurship (MGT602)

Quiz will cover video lecture no. 1 to 26

Schedule

Opening Date and Time

Dec 29, 2010 At 12:01 AM (Mid-Night)

Closing Date and Time

Dec 31, 2010 At 11:59 PM (Mid-Night)

24 hours extra time is not available