Salt is unique (usually random) data passed into a hash function for password storage to avoid the possible usage of rainbow tables or similar attacks. Salt will not help against dictionary or brute force attacks, as the salt is usually stored together with the hash.

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How does the possible attack on passwords and salts mentioned in PKCS#5 v2.1 work?

From PKCS#5 v2.1, 4.1 Salt (page 6, emphasis by me), also in v2.0, RFC 2898: In password-based encryption, the party encrypting a message can gain assurance that these benefits are realized ...
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KDF with low-entropy salts

I need to derive a key from a username and a password. These are the only two things I have access to. What I thought is using PBKDF2 with username as the salt and password as the master password. ...
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Injecting salt into PyCrypto KDF - useful?

I have noted some sources indicate that when using a KDF like PBKDF2 (alternatively) some advocate injecting the salt at the time of execution - like this: ...
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Knowing a valid salted hash for an unknown secret, is it possible to compute another valid hash?

$H(s,r)=d$ is a function that hashes the secret string $s$ with a salt $r$, and returns a digest $d$. $r$ may be arbitrarily chosen and each $r$ returns a different $d$. For any $d$, $r$ is known from ...
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How to use salt if I am sending hashed password?

If have application that is sending username and hashed password to server for authentication, how would I use salt for this scenario ?
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Hashing passwords with a salt - why use different salt for everyone?

Given a database where we have usernames and passwords, we want to secure users' passwords by hashing them. We should not use only username and passwords in this hash, as someone having data from ...
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How to salt PBKDF2, when generating both an AES key and a HMAC key for Encrypt then MAC?

When using Encrypt-then-MAC with AES and HMAC by password, and given 128 bits of payload with the ciphertext to store a random salt, which would be more secure: Using PBKDF2 with then entire 128 bit ...
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Should I salt an AES password at each encryption?

I saw a sample code where the same password is salted with a different value (using PBKDF2) for each encryption. That means that the salt must be stored for each encrypted message. I don't understand ...
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PBKDF2 and salt

I want to ask some questions about the PBKDF2 function and generally about the password-based derivation functions. Actually we use the derivation function together with the salt to provide ...
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Salting when encrypting?

I was attending a database encryption session at a developers conference. The presenter (who was a published author on the subject) said that MS SQL Server did not support salted hashes in the ...
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Do I have to have a different salt for each password?

Should I use a different salt for each password? In my system, there are no user names, only passwords. When a user logins in, he types in one or more passwords and the server compares the results ...
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268 views

Why not encrypt salt?

Assuming I had to distribute salt+ciphertext together over an insecure channel, isn't it better to store the salt encrypted? By encrypted I mean with a block cipher and with key and IV derived from ...
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Why x00 is usually avoided in salt?

In .NET Framework, there is a cryptographic Random Number Generator (RNG) provider which enables to generate a cryptographically strong sequence of random bytes. This provider contain, among others, ...
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Is there a standard for OpenSSL-interoperable AES encryption?

Many AES-encrypted things (files, strings, database entries, etc.) start with "Salted__" ("U2FsdGVkX1" in base64). I hear it's some sort of OpenSSL interoperability thing a b c. Is there some ...
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Use of salt to hash a password

In a few implementations of hashed passwords, I have seen that the length of the random salt is chosen to be, say, 10 or "some constant". Is there any specific reason why the salt is chosen to have a ...
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How much bigger does a precomputed lookup table get when salt is added?

I am trying to wrap my head around the benefits of salt in cryptography. http://en.wikipedia.org/wiki/Salt_(cryptography) I understand that adding salt makes it harder to precompute a table. But ...
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What's the reason for applying the hash twice when hashing with salt?

One of the typical approaches to computing a salted hash is this: hash(salt+hash(secret)) where hash is something like SHA-256 hash function - taking any size ...
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Is a using salt important when creating a hash data validator?

I am creating a service that will return an set of objects, which will be used by multiple systems. At the end of the process, one (or more) of the objects will be sent back to our system for ...
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870 views

Passwords with same SALT. What does this mean?

If the same SALT is used for many passwords on a Linux server, in what way is that a security risk? Does the mean, that a user (which can change his own password) can calculate other users passwords? ...
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Does the position of the salt improve its effectiveness when hashing?

Seems most documentation I have read suggests the salt should prefix the value to be hashed. Is this just for consistency, or is the salt more effective when prefixed?
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In storing passwords in a database should I use a per-application salt in addition to a per-secret salt?

Assuming that the salts are sufficiently long (16 random chars) is there any advantage in using a per-application salt in addition to a per-secret salt when storing hashed passwords in a database? ...
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How can I make my cipher show the avalanche effect?

I am a beginner in cryptography. I designed an password based encryption-decryption algorithm, which uses a random salt and a password to encrypt a message. I'm using SHA-512 for hashing, matrix ...
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How can a random salt for a hash function work in practice?

I understand the theory behind the use salts in hash functions, but when I see it implemented, the implementations always generate the salt on the fly and the salt appears to be different for every ...