Exam 21: Public-Key Cryptography and Message Authentication

Versions of SHA,with hash value lengths of 256,384,and 512 bits, (SHA-256,SHA-384,and SHA 512)are collectively known as _________.

SHA-3 algorithms must be designed to resist any potentially successful attack on SHA-2 functions.

In 2005,NIST announced the intention to phase out approval of _______ and move to a reliance on the other SHA versions by 2010.

The Diffie-Hellman algorithm depends for its effectiveness on the difficulty of computing discrete logarithms.

Although the _________ attack is a serious threat,there are simple countermeasures that can be used such as constant time calcs,random delays or blinding computations.

The Secure Hash Algorithm (SHA)was developed by the _________ and published as a federal information processing standard (FIPS 180)in 1993.

Perhaps the most widely used public-key algorithms are _________ and Diffie-Hellman.

If speed is a concern,it is fully acceptable to use _________ rather than SHA as the embedded hash function for HMAC.

The principal attraction of __________ compared to RSA is that it appears to offer equal security for a far smaller bit size,thereby reducing processing overhead.

Issued as RFC 2104,__________ has been chosen as the mandatory-to-implement MAC for IP Security.

Unlike RSA,DSS cannot be used for encryption or key exchange.

A ________ attack involves trying all possible private keys.

__________ are alarming for two reasons: they come from a completely unexpected direction and they are a ciphertext-only attack.

The evaluation criteria for the new hash function are: security,_______,and algorithm and implementation characteristics.

A hash function such as SHA-1 was not designed for use as a MAC and cannot be used directly for that purpose because it does not rely on a secret key.

The one-way hash function is important not only in message authentication but also in digital signatures.

The security of any MAC function based on an embedded hash function depends in some way on the _________ strength of the underlying hash function.

The __________ uses an algorithm that is designed to provide only the digital signature function and cannot be used for encryption or key exchange.

The key exchange protocol is vulnerable to a man-in-the-middle attack because it does not authenticate the participants.

SHA is perhaps the most widely used family of hash functions.