7.3 Hashing

Hash

A function that converts a variable-length string into a compressed, fixed-length value known as a message digest or hash.

Hash collision

A hash collision occurs when two files generate the same hash.

What are some common uses for hashing?

File Integrity, Digital signature and Secure logon credential exchange

Which of the following is a message authentication code that allows a user to verify that a file or message is legitimate? - MD5 - HMAC - RIPEMD - SHA

HMAC

Which of the following is used to verify that a downloaded file has not been altered? - Asymmetric encryption - Symmetric encryption - Hash - Private key

Hash

A birthday attack focuses on which of the following? - Hashing algorithms - VPN links - Encrypted files - E-commerce

Hashing algorithms

Rainbow table

A rainbow table is a table of passwords and their generated hashes.

What type of attack takes advantage of hash collisions?

Birthday attacks

When two different messages produce the same hash value, what has occurred? - Hash value - Birthday attack - High amplification - Collision

Collision

Hashing algorithms are used to perform which of the following activities? - Create a message digest. - Provide for non-repudiation. - Encrypt bulk data for communications exchange. - Provide a means for exchanging small amounts of data securely over a public network.

Create a message digest.

What are the five characteristics of a hash function?

Deterministic, Quick and efficient, One-way, Collision resistant, and Avalanche effect

What is the output of hashing called?

Digest or hash

Which of the following is the weakest hashing algorithm? - AES - SHA-1 - MD5 - DES

MD5

What are the main hashing algorithms used?

MD5, SHA, HMAC, and RIPEMD.

An attacker is attempting to crack a system's password by matching the password hash to a hash in a large table of hashes he or she has. Which type of attack is the attacker using? - RIPEMD - Brute force - Cracking - Rainbow

Rainbow

Which of the following does not or cannot produce a hash value of 128 bits? - SHA-1 - MD5 - RIPEMD - MD2

SHA-1

What is the process of adding random characters at the beginning or end of a password to generate a completely different hash called? - Deterministic - Salting - Avalanche - Collision

Salting

You have just downloaded a file. You create a hash of the file and compare it to the hash posted on the website. The two hashes match. What do you know about the file? - Your copy is the same as the copy posted on the website. - You can prove the source of the file. - You are the only one able to open the downloaded file. - No one has read the file contents as it was downloaded.

Your copy is the same as the copy posted on the website.