Security & Cryptography Surprise Tes

What is symmetric key cryptography?

• It requires a public key for encryption.

• It uses different keys for encryption and decryption.

• It is only used for digital signatures.

• Symmetric key cryptography uses the same key for encryption and decryption.

Answer explanation

Symmetric key cryptography is defined by the use of the same key for both encryption and decryption, making it distinct from asymmetric methods that use a public and a private key.

Name one advantage of symmetric key cryptography.

• Slower processing speed for large data.

• Requires more computational resources than asymmetric cryptography.

• Increased complexity in key management.

• Efficiency in processing large data.

Answer explanation

One advantage of symmetric key cryptography is its efficiency in processing large data, as it typically requires less computational power compared to asymmetric cryptography, making it faster for encrypting and decrypting large volumes of information.

What is the main disadvantage of symmetric key cryptography?

• Inability to encrypt large data sets.

• High computational overhead.

• Lack of authentication mechanisms.

• Key distribution and management challenges.

Answer explanation

The main disadvantage of symmetric key cryptography is key distribution and management challenges. As the number of users increases, securely sharing and managing keys becomes complex and poses significant risks.

Define asymmetric key cryptography.

• Asymmetric key cryptography uses a single key for both encryption and decryption.

• Asymmetric key cryptography is a method that relies solely on symmetric keys.

• Asymmetric key cryptography is a technique that does not involve any keys for securing data.

• Asymmetric key cryptography is a method of encryption that uses a pair of keys, one public and one private, to secure data.

Answer explanation

Asymmetric key cryptography uses a pair of keys: a public key for encryption and a private key for decryption, ensuring secure data transmission. The other options incorrectly describe symmetric key methods or no key usage.

How does public key cryptography enhance security?

• It uses a pair of keys for secure encryption and decryption, ensuring only intended recipients can access the information.

• It encrypts data using a simple password for access.

• It uses physical tokens to secure data transmission.

• It relies on a single key for both encryption and decryption.

Answer explanation

Public key cryptography enhances security by using a pair of keys: a public key for encryption and a private key for decryption. This ensures that only the intended recipient, who possesses the private key, can access the information.

What is a hash function used for in cryptography?

• To generate random passwords for users.

• To ensure data integrity and authenticity by producing a unique fixed-size output for input data.

• To compress data for faster storage.

• To encrypt data for secure transmission.

Answer explanation

A hash function in cryptography ensures data integrity and authenticity by producing a unique fixed-size output for any input data. This allows verification of data without revealing the original content.

Explain the properties of a good hash function.

• A good hash function must produce the same output for different inputs.

• A good hash function should be slow to compute for security.

• A good hash function is deterministic, fast, collision-resistant, irreversible, and exhibits the avalanche effect.

• A good hash function is always reversible and predictable.

Answer explanation

A good hash function is deterministic (same input yields same output), fast to compute, collision-resistant (different inputs produce different outputs), irreversible (cannot retrieve input from output), and exhibits the avalanche effect (small input changes cause drastic output changes).

What is the purpose of a digital signature?

• To compress the file size of the document.

• To add a watermark to the document.

• To verify authenticity and integrity of a message or document.

• To encrypt the message for secure transmission.

Answer explanation

A digital signature is used to verify the authenticity and integrity of a message or document, ensuring that it has not been altered and confirming the identity of the sender.

How does a digital signature ensure data integrity?

• A digital signature ensures data integrity by allowing the recipient to verify that the data has not been altered during transmission.

• A digital signature adds a watermark to the data for identification purposes.

• A digital signature compresses the data to save bandwidth during transmission.

• A digital signature encrypts the data to prevent unauthorized access.

Answer explanation

A digital signature ensures data integrity by allowing the recipient to verify that the data has not been altered during transmission, confirming its authenticity and reliability.

What is Public Key Infrastructure (PKI)?

• Public Key Infrastructure (PKI) is a system that manages digital keys and certificates to enable secure communication and authentication.

• A protocol for transferring files over the internet.

• A type of software for managing databases.

• A method for encrypting physical documents.

Answer explanation

Public Key Infrastructure (PKI) is essential for managing digital keys and certificates, facilitating secure communication and authentication, making it the correct choice. The other options do not accurately describe PKI.