Which components does HMAC use to determine the authenticity and integrity of a message? (Choose two.)

The correct answer is B. The hash C. The key. An HMAC is a MAC which is based on a hash function. The basic idea is to concatenate the key and the message, and hash them together. Since it is impossible, given a cryptographic hash, to find out what it is the hash of, knowing the hash (or even a collection of such hashes)…

Security Concepts

Question

Options

AThe password
BThe hash
CThe key
DThe transform set

How the community answered

(63 responses)

A
6% (4)
B
89% (56)
D
5% (3)

Explanation

An HMAC is a MAC which is based on a hash function. The basic idea is to concatenate the key and the message, and hash them together. Since it is impossible, given a cryptographic hash, to find out what it is the hash of, knowing the hash (or even a collection of such hashes) does not make it possible to find the key. The basic idea doesn't quite work out, in part because of length extension attacks, so the actual HMAC construction is a little more complicated.

Topics

#HMAC#message authentication#hash#integrity key

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