## Ethical Hacking Quiz 7

Which of the following statements is true for Masquerade attack?

A. In this attack, some portion of message is altered on its way.

B. In this attack, an attacker prevents access of resource to its legitimate users.

C. In this attack, the attacker pretends as a legitimate entity.

A. In this attack, some portion of message is altered on its way.

B. In this attack, an attacker prevents access of resource to its legitimate users.

C. In this attack, the attacker pretends as a legitimate entity.

The correct statement is: In a Masquerade attack,

**the attacker pretends as a legitimate entity**.
Which of the following is an example of passive security attack?

A. Traffic analysis

B. Replay

C. Modification

D. Denial of Service

A. Traffic analysis

B. Replay

C. Modification

D. Denial of Service

The correct example of a passive security attack is

**Traffic analysis**.
Which of the following statement(s) is/are true?

A. In symmetric key cryptography, separate keys are used by sender and receiver.

B. In symmetric key cryptography, a single key is used by sender and receiver.

C. In asymmetric key cryptography, separate keys are used by sender and receiver.

A. In symmetric key cryptography, separate keys are used by sender and receiver.

B. In symmetric key cryptography, a single key is used by sender and receiver.

C. In asymmetric key cryptography, separate keys are used by sender and receiver.

The correct statements are:

**In symmetric key cryptography, a single key is used by sender and receiver**, and**in asymmetric key cryptography, separate keys are used by sender and receiver**.
Consider the following statement:

(i) In symmetric key cryptography, the security depends on secrecy of the key.

(ii) In symmetric key cryptography, the security depends on the secrecy of the encryption/decryption algorithm.

(i) In symmetric key cryptography, the security depends on secrecy of the key.

(ii) In symmetric key cryptography, the security depends on the secrecy of the encryption/decryption algorithm.

**Only (i) is true**.

25 parties want to exchange messages securely using a private key encryption algorithm. The number of distinct key values required will be ________.

The correct number of distinct key values required is

**300**.
Consider a cipher text “GVCTXSKVETLC” encrypted using a substitution cipher approach, where each letter is replaced by the k-th next letter.

Assumption:

(i) The alphabets are wrapped around, i.e. Z is followed by A.

(ii) Each alphabet (A to Z) is assigned a number (1 to 26).

(iii) The value of secret key k is 4. What will be the plain text?

Assumption:

(i) The alphabets are wrapped around, i.e. Z is followed by A.

(ii) Each alphabet (A to Z) is assigned a number (1 to 26).

(iii) The value of secret key k is 4. What will be the plain text?

The plain text for the given cipher text is

**CRYPTOGRAPHY**.
Consider a mono-alphabetic cipher with the following key value: (ABWXEFSTIJOPMNKLQRGHUVCDYZ)

What will be the encrypted form of the message “ALPHABETIC”?

What will be the encrypted form of the message “ALPHABETIC”?

The encrypted form of the message “ALPHABETIC” is

**APLTABEHIW**.
If a sender A wants to carry out encryption on a message and send it to receiver B using public-key cryptography, which of the following key will be used for decryption at receiver end B?

A. A’s public key

B. A’s private key

C. B’s public key

D. B’s private key

A. A’s public key

B. A’s private key

C. B’s public key

D. B’s private key

The key used for decryption at receiver end B is

**B’s private key**.
The effective key length used in the AES encryption algorithm can be:

A. 64 bit

B. 128 bit

C. 192 bit

D. 256 bit

A. 64 bit

B. 128 bit

C. 192 bit

D. 256 bit

The effective key lengths used in AES are

**128 bit**,**192 bit**, and**256 bit**.
50 parties want to exchange messages securely using some public key encryption technique like RSA. The number of distinct key values required will be ________.

The number of distinct key values required will be

**100**.**Also Available:**

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