Cryptography GCSE

What is the purpose of cryptography in computer science?

• To make information easily accessible to everyone

• To slow down computer processing speed

• To secure and protect sensitive information

• To create complex puzzles for entertainment purposes

Explain the difference between symmetric and asymmetric encryption.

• Symmetric encryption uses different keys for encryption and decryption

• Symmetric encryption is more secure than asymmetric encryption

• Asymmetric encryption uses the same key for both encryption and decryption

• Symmetric encryption uses the same key for both encryption and decryption, while asymmetric encryption uses a pair of public and private keys.

What is a key in the context of cryptography?

• A piece of information used to encrypt and decrypt data

• A type of musical instrument

• A type of door lock

• A type of food seasoning

Describe the process of encryption and decryption.

• Encryption is the process of converting ciphertext into plaintext using an algorithm and a key. Decryption is the process of converting the plaintext back to ciphertext using the same algorithm and key.

• Encryption is the process of converting plaintext into ciphertext using an algorithm and a key. Decryption is the process of converting the ciphertext back to plaintext using the same algorithm and key.

• Encryption and decryption are the same process, just with different names.

• Encryption and decryption do not require the use of an algorithm or key.

What is the significance of the Caesar cipher in the history of cryptography?

• It is one of the earliest known substitution ciphers and laid the foundation for more complex encryption methods.

• It was only used by a small group of people and had no impact on cryptography

• It was quickly replaced by more advanced ciphers and became obsolete

• It was never used in any significant historical events

Explain the concept of a digital signature in cryptography.

• A digital signature is a handwritten signature on a digital document.

• A digital signature is a cryptographic technique used to verify the authenticity and integrity of a digital message or document.

• A digital signature is a type of encryption used to hide the contents of a digital message.

• A digital signature is a method of compressing digital files to save storage space.

What are the common types of cryptographic attacks?

• Social engineering, denial of service, and SQL injection attacks

• Trojan horse, worm, and rootkit attacks

• Brute force, dictionary, and man-in-the-middle attacks

• Phishing, malware, and ransomware attacks

Discuss the importance of public key infrastructure (PKI) in cryptography.

• PKI has no role in authenticating user identity

• PKI is only important for managing private keys

• PKI is important for managing and distributing public keys, authenticating user identity, and ensuring data security.

• Data security can be achieved without PKI

What is the role of cryptographic hash functions?

• To send secret messages

• To compress large files

• To create visual effects in video games

• To securely store passwords, verify data integrity, and generate digital signatures.

How does quantum cryptography differ from traditional cryptography?

• Quantum cryptography is based on classical physics

• Quantum cryptography uses ancient encryption methods

• Quantum cryptography relies on physical keys for security

• Quantum cryptography uses quantum mechanics principles to secure communication.