FIT2093 Quiz Week 8

An important component of efficient digital signatures is a ____________.\ Select one: a. shared private key b. two-way hash function c. cryptographic hash function d. MAC

c

An important security property of cryptographic hash functions used in digital signatures is _____________. Select one: a. privacy b. confidentiality c. collision resistance d. pseudorandomness

c

Secure digital signatures protect against integrity attacks that copy the signature from one document into another document by ________. Select one: a. making signatures an image of a handwritten signature b. making signatures independent of the message c. making signatures dependent on the message d. none of the above

c

With a __________ attack the attacker is given access to the signatures of messages selected by the attacker. Select one: a. key-only b. known message c. chosen message d. no message

c

A disadvantage of MACs compared to digital signatures is ____________. Select one: a. none of the above b. MACs are slower c. MACs use public keys d. MACs are not publicly verifiable

d

Insertion of messages into the network from a fraudulent source is a __________ attack. Select one: a. source repudiation b. content modification c. sequence modification d. masquerade

d

_______ is a standardised method to turn a cryptographic hash function into a MAC. Select one: a. CMAC b. EMAC c. AES d. HMAC

d

__________ assures that data received are exactly as sent and that the claimed identity of the sender is authentic. Select one: a. public key cryptography b. message authentication c. hash d. message encryption

b

An example of a block cipher mode of operation that implements a MAC for integrity protection is ______. Select one: a. CMAC b. CTR c. CFB d. CBC

a

In RSA digital signatures, the __________ is formed by taking the hash of the message and exponentiating the message to the power of the signer's private key d. Select one: a. digital signature b. timestamp c. message digest d. hash code

a

To protect both authenticity and confidentiality of a message using public key cryptography, the sender should _________. Select one: a. sign the message with sender's private key, then encrypt with recipient's public key b. sign the message with sender's public key, then encrypt with recipient's public key c. sign the message with sender's public key, then encrypt with recipient's private key d. sign the message with sender's private key, then encrypt with recipient's private key

a

A necessary assumption for security of a digital signature against forgery attacks is that ____________. Select one: a. none of the above b. the signer's private key is not known to the attacker c. the signer's public key is used by the signer for signing d. the signer's public key is not known to the attacker

b

For a brute force collision attack against a hash function with n-bit digest length to succeed with high probability, an attacker would need to hash about ______ random messages. Select one: a. 2^n b. 2^n/2 c. 2^n/3 d. none of the above

b

MACs do not achieve non-repudiation against the sender because _________. Select one: a. the MAC is unforgeable b. the receiver can also forge a MAC c. only the sender can produce a MAC d. the MAC is publicly verifiable

b

The MAC function is a __________ function. Select one: a. one-to-two b. many-to-one c. one-to-one d. one-to-many

b