Questions tagged [salt]
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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Salts are stored with the hash - so for a single user it's no security advantage?
A hacker goes into a database and downloads a bunch of hashes and salts of users with knowledge of the hashing method. Say this is one entry that got downloaded:
cbc0a790b2f28fc72ca43eb749028b9f:...
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What is the impact of leaving a salt used in HKDF open to attacker control? [duplicate]
RFC 5869 for HKDF says "an application needs to make sure that salt values are not chosen or manipulated by an attacker".1 Soatok also discusses some nuances in choosing salts for HKDF.2 ...
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How can knowledge of a secret be compared among untrusted entities?
Lets say entity A sends a secret "token" to anybody that they trust.
The token itself is the proof and its sent equally to everybody and it has or needs to be derived from application ...
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Can salt and XOF be used to create a symmetric cipher? [duplicate]
I'm new to crypto, and I've got an idea and I want to get some feedback if it's even a right direction. Let's say that I create a symmetric cipher by using an XOF with a salt and a secret key.
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Does having multiple salted hashes lower pre-image resistance?
A common method to mitigate the effect of rainbow tables is to add a string to the end of the user password before hashing, a process known as salting.
However, let’s say for example that someone uses ...
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Digital signature and salt
I'm wondering whether is of any use to add salt when computing a signature of a piece of data.
I looked around but didn't find an answer to this, although there's a very similar question: Why hash or ...
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Can salt just be appended to the password before hashing?
I am currently developing the back end of a website for one my projects and needed to store passwords. I knew that I needed to store passwords with salt, and my initial approach was to just generate ...
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Benefit of salt in KDF like Argon2
I don't understand why I need a salt for Argon2 if Argon2 is only needed as a KDF for a password which is then called AES. At the end neither the password nor a password hash is stored. Only the data ...
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Using Argon2, can I improve the salt join the password Argon(password,password+salt)?
I'm creating an application where I'm going to use Argon2, I'm going to have a password, and I'm going to use as salt: email+name+date of birth, you must think that my salt is silly because name and ...
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Finding out the hashing algorithm and salt if you know the password and the resultant hash
If I have the password and hash will I be able to find out the Hashing algorithm and salt used. What tools can I can use? Will hashcat work?
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Password Hashing based on Common Passwords
If an attacker has a database of 1,000 users' hashed passwords which are hashed with SHA-256 with a 128-bit salt and all of these users used 10,000 common passwords. How many hashes will the hacker ...
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Password hashing and salting with SHA-256 on $2^{64}$ password space
If a password is randomly chosen from a space of $2^{64}$ passwords and is stored as an SHA-256-bit hash and a 128-bit salt, how many hashes does an attacker need to perform to recover the password in ...
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How many hashes to recover a salted password? [closed]
If a password p is selected from a space of 2^64 passwords, and the server stores this as a hash, h = SHA-256(p||s) where s is a random 128-bit salt. How many maximum hashes would an attacker need to ...
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Do we also have to transmit the salt with the ciphertext, in addition to the IV for authenticated point to point messaging?
Imagine a scenario whereby Alice and Bob have a symmetrical messaging system for talking with each other. It's effectively two polystyrene cups joined by a piece of string. Crucially, there is no ...
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How long does it take to decrypt AES encrypted message with salt(for pbkdf2 key) and iv known
I'm new to crypto!
The situation is,
Aes-256-cbc encrypted message(including not encrypted iv & salt) is revealed.
We also know pbkdf2 function uses 10000 rounds with sha256.
All we need to ...
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Question about PBKDF salts and cryptographically secure randomness
I have seen a few answers here and elsewhere that say a salt doesn't need to be cryptographically secure randomness but rather just unique since they are stored in the open anyway. I am working on an ...
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How can I add metadata to Tink Keys?
I'm planning to use tink to encrypt records stored in a database. I also plan to hash specific values from the records in order to be able to find records by field values. In order to avoid rainbow ...
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Does a salt by a trusted party remove the need for collision resistance for a binding commitment?
Say a Human is operating their trusted computer, Alice, and Human wants to hand copy a collision resistant commitment, with a security factor of 128 from Bob on to paper. Naturally we want the ...
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Minimum length of salt and info for HKDF
Hi newbie here is there any minimum length for salt and info passed to hkdf based key derivation or is using 32 byte randomly generated bits for salt and info can be used for all hkdf
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Argon2id creating key for cryptography, how acceptable is it to use the same salt for the same encryption operation?
Everyone knows Argon2id is a slow hashing algorithm, and that's on purpose, all is good.
When creating an Argon2id object a lot of parameters are needed to be taken into consideration ultimately ...
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Salt value in scrypt algorithm
I see there are a lot of questions relating to handling of a salt value but nothing I have seen so far has cleared the following question.
When using a KDF such a scrypt, I believe the value of the ...
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How safe is my pseudonymization procedure?
I work for an institution where patient data is collected and I am supposed to encrypt it. At the moment I do the following steps (with R):
Randomly assigning an ...
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Benefits of hashing a particular seed in a PRNG
This question is linked with this question (stackoverflow) where I asked about a specific implementation detail of Python's random number generator (Mersenne Twister). Here, I have a slightly ...
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XChaCha20 With a Zeroed Nonce?
We know that for ChaCha20 and XChaCha20, the same key can never be used with the same nonce. But let's say I use a random 256-bit key every time... Then the nonce can be whatever because the key is ...
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Applications in which you should/shouldn't use a salt with HKDF
rfc5869 has the following to say about the use or lack thereof of salts with HKDF:
HKDF is defined to operate with and without random salt. This is done to accommodate applications where a salt value ...
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Can the salt be derived based on the other components of encrypted data?
I'm using python.cryptography's Fernet with PBKDF2 passphrase hashing to encrypt a piece of data (the value) that is stored, encrypted, in a database. The hashed passphrase is not stored in the ...
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if i enter a password that's incorrect but that collides with one when hashed, will it let me in?
suppose no salt or pepper is used and passwords are hashed plain, will entering incorrect password that just hashes to the same let me in? i know that one use of salting/peppering techniques is to, ...
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Necessity of PBKDF2 in current Setup?
I have a single password which is random bytes that encrypts a database. Right now I am using an encryption scheme of https://gist.github.com/jbtule/4336842. To summarize, we take our one password, ...
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Should I protect the salt before storing it in a database or use a pepper (secret salt) instead?
If I protected the salt or used a pepper (secret salt) and an attacker got access to the database he can't do a rainbow table attack on a targeted user (a famous or important person).
Should I use a ...
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Does my SHA-256 TableSalt algo give away the seed salt?
The Setup
I have a table of values for which I need to compute a salted hash for each table-cell value. Furthermore, I need the salt for each table cell to be unique and unpredictable. (I can explain ...
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7-Zip Encryption: Practical Effect of Lacking Salt
A previous discussion on Cryptography StackExchange leads me to understand that 7-Zip does not use salt to derive an encryption key from password to use its AES-256 encryption; that this is a ...
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Adding salt to Blake3 Key derive function
According to the whitepaper, Blake3 can be used as a key derivation function (function key_derive). Currently, as a key ...
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Secure AES IV with static salt
I have an (offline) shared secret key (symmetric) which is used to encrypt/decrypt data.
Now this data belongs to a specific user which is known on the backend and frontend. My idea was to use the ...
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Do I need a salt for Scrypt if the data is client-side?
I have a web app, in which I am encrypting user data client side. Each client has their own password, which is used to derive an encryption key (via Scrypt) for encrypting their data. Since the data ...
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Match bcrypt hash with plaintext
I have a bcrypt hash: $2b$10$kn7yEh2nYiDqDYNY.hjiZOtASBKT9uO4KozbFWDW2XLYnW58nkpq and a list with given plaintext passwords. How can I get the password from the ...
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Do you use a salt when encrypting a password or just when hashing a password?
A password is used to connect to a database.
This password is kept in a file.
This password (therefore) needs to be encrypted.
A program to access the aforementioned database needs (of course) the ...
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Best way to derive a MAC key without a salt
It's best to use separate keys for encryption and the MAC.
Most implementations tend to derive a larger key and split it in two (e.g. scrypt with an output of 32 + 64 = 96).
Alternatively, you can ...
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Can I use ChaCha20-Poly1305 as my KDF?
I have two devices that use a PSK. One is embedded and extremely resource confined. I'm already using ChaCha20-Poly1305 so it would be "free" to reuse this. There is no transport encryption ...
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Best practise for encryption in a password manager
I'm trying to make a password manager for Windows installed computers, and after researching the best ways to encrypt the passwords in the database (I'm new to cryptography) I think I've come up with ...
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Static salt for PBKDF2, but unique salt for HKDF?
Hypothetical. Lets say you have an application where you generate a master key from a user password using PBKDF2 (static salt) and then use the master key to derive two passwords keys for an encrypt-...
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Which is the better way of generating a salt string?
Using T-SQL as per the snippets below, which method is superior (or is it a tie)?
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Salt length in SHA-512 version of Unix crypt command
SHA-512 crypt specs reports that SHA-512 crypt uses 128bit salt.
The FreeBSD/Linux password generation code builds the salt using 16 bytes random data (128bits) and then it translates the random data ...
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Is my password database encryption flow secure?
I'm not an expert and I would be very glad if someone could take a look at it and tell if there are any problems with it
Things I know/think are problematic
using base64 digest + getting the first 32 ...
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Random salt and PBKDF2 key
Suppose I wrote a function $$(salt,IV ) = \text{keyIVGenerator}(passwd)$$ which generates a random salt of size 32-bytes and a random Initialisation Vector (IV) of size 16-bytes. Then, use a Key ...
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Using a nonce as a salt for key derivation
I'm currently playing a bit with PyNaCl (python binding to libsodium) and I want to use the secretbox for symmetric encryption between two parties, which means they both must know the (in my case ...
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Could a fixed RSA encryption be used instead of a salt to prevent rainbow table attacks?
It's common to use a salt before hashing a password in order to prevent an attack by rainbow tables.
Would it also work to encrypt the password for instance by RSA encryption - by a permanent RSA ...
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Difference between server salt and client salt?
Basically I am trying to understand the difference between server salt and client salt. I know that the client salt is used to make encryption harder for hackers, but I can't seem to grasp the concept ...
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Salt: best practice
I'm a complete novice at this and in need of advice. I'm building an app that I've implemented a password encrypted backup feature into. I'm wondering about the best practice for handling the salt. ...
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Is storing salts encrypted a good idea?
I've read that storing password hashes in a database, you can store the salt in plaintext alongside the actual hash with no detriment to security. I was thinking that one could derive a key from the ...
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Is AES ECB mode with salt and frame counter still comparatively weak?
Many advice against using AES in ECB mode as it always produces same cipher text for a given plain text.
That shortcoming can be addressed by using salt appended to original message so that the ...
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