Page 246 - DCAP403_Operating System

Unit 12: Security Solution

Fill in the blanks: Notes

3. A digital certificate is data that functions much like a ....................... .

4. A certifying authority creates the digital certificate and digitally signs it using its own

....................... .
5. ....................... is defined as a method to verify (ex. Public Key’s) electronically for

authenticity.
6. A key in cryptography is a long sequence of bits used by ....................... algorithms.
7. One key encodes the message and the other ....................... it.

8. Encryption information helps prevent it by ....................... .
9. The number of keys each algorithm can support depends on the number of bits in the
....................... .
10. ....................... schemes are generally categorized as being either stream ciphers or block
ciphers.

12.16 Review Questions

1. Explain the concept of digital encryption standards
2. Write short note on RSA system

3. Briefly explain digital signature in details
4. What do you mean by digital certifi cate?
5. What do you understand by secret key cryptography? Explain with the help of suitable
diagram.

6. Distinguish between DES and Triple-DES techniques.
7. “Symmetric cryptography can also be used to address the integrity and authentication
requirements.” Explain

8. Explain the process of verification of digital signature.

9. “Stream ciphers operate on a single bit at a time and implement some form of feedback
mechanism so that the key is constantly changing.” Discuss
10. Write short note on “Cipher Block Chaining”.

Answers: Self Assessment

1. (b) 2. (a) 3. physical certifi cate
4. private key 5. Digital certifi cate 6. encryption/decryption
7. decodes 8. unauthorized user 9. key
10. Secret key cryptography

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