Page 227 - DCAP207_NETWORKS_DCAP406_COMPUTER_NETWORKS

Computer Networks/Networks

Notes IP-spoofing: Like honeypots, IP spoofing involves the interception of data packets by a computer
successfully pretending to be a trusted server/resource.
Maliciously: Coded Websites - Maliciously coded Websites create chartable websites enabling
a user to make donations and thus stealing the vital personal information.
Packet Sniffers: Packet sniffers are the technique used to capture data streams over a network to
obtain sensitive data like usernames, passwords, credit card numbers, etc.
Password Attacks: A ‘Password Attack’ includes a number of techniques used by hackers to
steal passwords.

Phishing: Emails with titles such as, “URGENT: Update Account Status” are all attempts by a
spammer to “phish” the account details.
Plaintext: It is the text message to be transmitted on which an algorithm is applied.

Private Key: The key of a key pair, which is used to create a digital signature. It can be used to
sign a message that only the corresponding public key can verify.
Public Key: It is the key of a key pair that is used to verify a digital signature. Key pair consists
of private and public key.
Secret Key: They constitute a part of algorithm for encryption and decryption of
the message.

14.8 Review Questions

1. What are different criterions to keep information private when it is sent over a public
network?
2. How does the encryption affect performance of network?
3. There are certain information bases on the Internet that need to be prevented by undesirable
person to get. How can undesirable person be kept from accessing this?
4. How do we keep our own and other people’s computers safe from hackers? Explain with
the help of a hypothetical situation.

5. What is a Cipher? Why are cipher used for large messages?
6. Describe briefly two kinds of security attacks, which can be directed against an Internet-
connected computer system.

7. What is the difference between secret key and public key encryption?
8. What is cryptography? What are the benefits of using this technique?
9. What do you mean by substitution and transposition ciphers? Differentiate between the
two.
Answers: Self Assessment

1. encryption and decryption 2. encryption
3. privacy 4. decrypt
5. IP spoofing 6. True
7. False 8. True

9. True 10. False

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