What is the main goal of cryptography?
a) To prevent unauthorized access to data
b) To increase the size of the data
c) To make data readable by unauthorized users
d) To reduce data storage space
Which of the following is an example of symmetric key encryption?
a) RSA
b) AES
c) ECC
d) DSA
What is a public key in asymmetric encryption used for?
a) To decrypt the data
b) To encrypt the data
c) To generate symmetric keys
d) To perform hashing operations
What is the primary purpose of a hash function in cryptography?
a) To encrypt data
b) To verify data integrity
c) To generate a key pair
d) To manage public key infrastructure
Which algorithm is commonly used for digital signatures?
a) DES
b) RSA
c) AES
d) Diffie-Hellman
Which of the following is a key difference between symmetric and asymmetric encryption?
a) Symmetric encryption uses the same key for encryption and decryption, while asymmetric uses a public and private key pair
b) Symmetric encryption is slower than asymmetric encryption
c) Asymmetric encryption is easier to implement
d) Symmetric encryption uses a public key, while asymmetric uses a private key
What is the main advantage of asymmetric encryption over symmetric encryption?
a) Faster encryption and decryption
b) No need to share secret keys securely
c) Easier implementation
d) Higher data compression
Which of the following is a widely used encryption algorithm in HTTPS?
a) DES
b) AES
c) RSA
d) Blowfish
Which cryptographic algorithm is considered the most secure for symmetric key encryption?
a) DES
b) AES
c) RC4
d) 3DES
What does a digital signature provide?
a) Confidentiality
b) Authentication and integrity
c) Data compression
d) Symmetric encryption
Which of the following is a commonly used hashing algorithm?
a) RSA
b) SHA-256
c) AES
d) Diffie-Hellman
What is the main purpose of the Diffie-Hellman key exchange protocol?
a) To encrypt data
b) To generate symmetric keys securely over an insecure channel
c) To sign data
d) To hash data
In which cryptographic system is a private key used to decrypt messages?
a) RSA
b) DES
c) AES
d) Elliptic Curve Cryptography
What is a one-way hash function?
a) A function that encrypts and decrypts data
b) A function that returns the same result for any input
c) A function that can be reversed with the correct key
d) A function that returns a fixed-length output and cannot be reversed
Which of the following is true about the AES encryption algorithm?
a) It uses a 512-bit key
b) It is a symmetric key algorithm
c) It is based on RSA principles
d) It is a hashing algorithm
What is the main difference between a block cipher and a stream cipher?
a) Block ciphers encrypt one bit at a time, while stream ciphers encrypt data in fixed-length blocks
b) Block ciphers encrypt data in fixed-length blocks, while stream ciphers encrypt one bit or byte at a time
c) Block ciphers use asymmetric encryption, while stream ciphers use symmetric encryption
d) There is no difference between block and stream ciphers
Which of the following is NOT a property of a good cryptographic algorithm?
a) It should be easy to break without the key
b) It should have high performance
c) It should resist known cryptanalysis attacks
d) It should use a large key size
What does “perfect forward secrecy” (PFS) ensure in encryption?
a) The encryption key is shared securely between parties
b) Past communications remain secure even if the private key is compromised in the future
c) The encryption algorithm is unbreakable
d) Data is encrypted with a unique key for each communication
What is the purpose of using a salt in hashing algorithms?
a) To increase the size of the output
b) To make the hashing process faster
c) To ensure that the hash is unique even for identical inputs
d) To encrypt the hash
Which type of encryption uses the same key for both encryption and decryption?
a) Asymmetric encryption
b) Symmetric encryption
c) Hashing
d) Digital signatures
What does the term “public key infrastructure” (PKI) refer to?
a) The physical hardware used to generate encryption keys
b) The system used to manage keys, certificates, and encryption processes
c) The method of encrypting messages using public keys
d) A type of hashing algorithm
What does RSA stand for in cryptographic terms?
a) Reliable Security Algorithm
b) Rivest-Shamir-Adleman
c) Random Symmetric Algorithm
d) Reversible Security Authentication
Which of the following is the main weakness of RSA encryption?
a) It is too slow for large amounts of data
b) It cannot be used for secure communication
c) It is not suitable for public key infrastructure
d) It uses too small key sizes
What is an example of a hybrid encryption system?
a) RSA only
b) AES with RSA
c) SHA-256 with AES
d) Blowfish with Diffie-Hellman
What is a digital certificate used for in cryptography?
a) To verify the identity of the sender and establish trust
b) To sign messages securely
c) To encrypt data with a public key
d) To generate hash values for verification
Which of the following best describes elliptic curve cryptography (ECC)?
a) It uses very large keys for security
b) It is a type of symmetric encryption
c) It is based on the algebraic structure of elliptic curves over finite fields
d) It is a hashing algorithm
What is the main purpose of key management in cryptography?
a) To securely store keys and prevent unauthorized access
b) To encrypt data using a shared key
c) To manage the process of hashing passwords
d) To generate cryptographic algorithms
Which of the following is an advantage of using elliptic curve cryptography (ECC) over RSA?
a) ECC uses shorter key sizes while providing the same level of security
b) ECC is easier to implement
c) ECC is not susceptible to quantum attacks
d) ECC is faster for large data encryption
What is the main characteristic of a “block cipher” encryption algorithm?
a) It encrypts data one bit at a time
b) It uses a single key for encryption and decryption
c) It divides plaintext into fixed-size blocks for encryption
d) It uses asymmetric keys for encryption
Which cryptographic technique is used to ensure that messages have not been altered during transmission?
a) Encryption
b) Hashing
c) Digital signatures
d) Both b and c
