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Does HMAC use a salt?
An HMAC incorporates additional secret data in the form of a key. This key is combined with the message in a much deeper way than a salt, and may be used in addition to a simple salt of the message.
What does HMAC put in a password to also make it safer from cracking?
An HMAC requires a secret key (sometimes called a pepper) as opposed to a salt, which is public. Otherwise it is not an HMAC; it is just a hash. A common use of an HMAC is to create a tamper-resistant fingerprint in order to provide message integrity.
What is HMAC sha256?
HMAC(Hash-based message authentication code) is a message authentication code that uses a cryptographic hash function such as SHA-256, SHA-512 and a secret key known as a cryptographic key. HMAC is more secure than any other authentication codes as it contains Hashing as well as MAC.
What’s the difference between a salt and a HMAC?
An HMAC incorporates additional secret data in the form of a key. This key is combined with the message in a much deeper way than a salt, and may be used in addition to a simple salt of the message.
What’s the difference between HMAC and a keyed hash?
HMAC is a Message Authentication Code, which is meant for verifying integrity. This is a totally different kind of beast. However, it so happens that HMAC is built over hash functions, and can be considered as a “keyed hash” — a hash function with a key.
Which is better a key or a salt?
A key is not a salt (keys are secret, salts are not). But the unique characteristics of HMAC make it a reasonable building block for other functions, which is what happens in PBKDF2: that’s a key derivation function, commonly subverted into password hashing (a role for which it appears to be adequate).
Can a secret salt be used to authenticate a message?
A “secret salt” for a public message, to produce a tamper-proof authenticated hash would work in theory, but in practice our hash functions are imperfect, and when used in this way they are vulnerable to attacks that add data to the original message and change the hash in a predictable way (a “length extension attack”).