Cryptography Concepts

What is the main difference between symmetric and asymmetric cryptography?

• The main difference is in the type of encryption algorithm used.

• The main difference is in the speed of encryption and decryption.

• The main difference is in the level of security provided.

• The main difference is in the number of keys used for encryption and decryption.

How do stream ciphers differ from block ciphers in terms of encryption?

• Stream ciphers encrypt data in fixed-size blocks, while block ciphers encrypt data bit by bit

• Stream ciphers encrypt data bit by bit or byte by byte, while block ciphers encrypt data in fixed-size blocks at a time.

• Stream ciphers and block ciphers both encrypt data in a continuous stream

• Block ciphers and stream ciphers both encrypt data in fixed-size blocks

What is the purpose of a hash function in cryptography?

• Hash functions are only used for compressing data in cryptography

• The purpose of a hash function is to decrypt messages in cryptography

• The purpose of a hash function in cryptography is to convert input data into a fixed-size string of bytes, used for data integrity verification, message authentication, and password storage.

• A hash function in cryptography is used to encrypt data with a private key

Describe the process of transposition in cryptography.

• Transposition in cryptography involves rearranging the order of characters in a message according to a certain system or key. This process does not change the characters themselves but alters their positions.

• Transposition involves changing the characters in a message to create an encrypted text.

• Transposition is a process of converting text into a different language.

• Transposition rearranges the words in a message alphabetically.

What is substitution in the context of cryptography?

• Substitution is a process of converting plaintext to ciphertext using a mathematical formula.

• Substitution in cryptography involves replacing each letter in the plaintext with another letter or symbol based on a key or algorithm.

• Substitution refers to the act of directly transmitting the plaintext without any encryption.

• Substitution involves rearranging the order of letters in the plaintext without any key or algorithm.

Explain how a Ceasar Cipher works and provide an example of its implementation.

• The Caesar Cipher works by reversing the order of letters in the plaintext

• The Caesar Cipher works by shifting each letter in the plaintext by a fixed number of positions down or up the alphabet. For example, with a shift of 3, 'HELLO' would be encrypted as 'KHOOR'.

• The Caesar Cipher works by doubling each letter in the plaintext

• The Caesar Cipher works by substituting each letter in the plaintext with a random symbol

What is the significance of key length in symmetric cryptography?

• Key length in symmetric cryptography determines the strength of encryption.

• Key length in symmetric cryptography determines the speed of encryption

• Shorter key lengths provide stronger encryption

• Key length in symmetric cryptography is irrelevant

How does public key cryptography differ from private key cryptography?

• Public key cryptography uses a private key for encryption and a public key for decryption, while private key cryptography uses the same key for both.

• Public key cryptography uses the same key for encryption and decryption, while private key cryptography uses two keys.

• Public key cryptography uses two keys, a public key and a private key for encryption or decryption, while private key cryptography uses the same key for both encryption and decryption.

• Public key cryptography does not involve encryption or decryption, while private key cryptography uses two keys for encryption and decryption.

Discuss the importance of data integrity in the context of cryptography.

• Data integrity is not important in cryptography

• Data integrity only affects the speed of encryption

• Data integrity is crucial in cryptography to maintain the confidentiality, authenticity, and reliability of the encrypted information.

• Data integrity is only relevant for physical security measures

Choose which can be achieved by implementing Cryptography.

• Non-Repudiation

• Authenticity

• Confidentiality, Integrity and Availability

• ALL as listed.