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Questions tagged [salt]

A salt is a random addition to a password to make the hashed password less susceptible to a lookup table attack

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2answers
154 views

Letting client encrypt his/her data. How to ensure the client doesn't lose his/her private data?

I am designing a web service where the client is allowed to encrypt his own data on client-side software & then send it to our server, so they can be sure their data is private on our side. Then, ...
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0answers
31 views

LUKS mitigate brute force attacks even if salt parameter is know?

From What users should know about Full Disk Encryption based on LUKS In Linux world, LUKS implementations are based on cryptsetup and dm-crypt. In order to mitigate the problem of brute ...
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23 views

Password Hashing - Where does the Salt gets stored [duplicate]

I have read that it is a best practice to store Hashed passwords using Hashing algorithms which uses Salt to protect from Rainbow table attack. My question is- if i store the hashed password in my ...
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1answer
41 views

Do I need to use salt with api key hashing?

I will generate api keys. I plan to store their hashes instead of plain text. do i also need salt, similar to storing password? AFAIK salt prevents rainbow table attack and those are more ...
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1answer
56 views

Password storage which avoids privileged insider attack

What are the standard password authentication protocols in client-server setting where authentication happens at the remote server? Is there any password/pin verification protocol which reveals zero ...
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1answer
158 views

Is hashing without a salt secure for random passwords? [duplicate]

I'm designing an API with token authentication. I don't want to store tokens as plain text in the database, for the same reason user passwords are not stored as plain text: if the database gets ...
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0answers
28 views

Is a combination of user login and site domain a sensible salt? [duplicate]

Just out of curiosity (since I know the established password hashing libraries should provide "proper" random salts), would a combination of the user login and the respective site's domain (or a hash ...
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1answer
45 views

Secure Register - Login Portal [closed]

Im trying to create a secure portal for parents to view their sons or daughters information. I would need to have a register page. Im having trouble with hashing and salting the password. Then I ...
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2answers
149 views

Appending a secret (pepper) to Argon2 password hashes

I've read quite a bit of the StackExchange and HackerNews debates on the user of "peppers" in password hash security. There are a number of different implementations of the idea of a pepper, ranging ...
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3answers
151 views

Hash pepper in web application possible?

I have read a few articles and several question on here about hashing correctly. While hashing, adding salt and especially pepper is primarily a server side use case, I am interested in the ...
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0answers
175 views

bcrypt.checkpw() returning true for different salt+hash

new user here. I've tried searching for an answer but I don't think I know the correct terms to search for. I've tried things like "bcrypt same password different hash" but can't find an answer to my ...
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2answers
310 views

How long does it take to compute hashes using the MD5 hash algorithm? [closed]

1) If one iteration of MD5 takes x seconds, is it safe to assume that n iterations of MD5 takes n * x seconds? 2) Will salted and unsalted versions of md5 hash algorithms take approximately the same ...
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1answer
483 views

hashcat - cracking a salted sha256

Given a SHA512 hash, a salt, and username I am trying to crack the hash using hashcat. Every example I've found used a hashfile as input, is there way to provide salt and hash via commandline without ...
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1answer
85 views

Best tool for cracking SHA-1s with unique pre and post salts? [closed]

I can't find a tool that supports cracking SHA-1s with different pre and post salts. Any suggestions?
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0answers
36 views

Where do salts come from? [duplicate]

A salt can be a random value and length. The hash and the salt are stored in the database. Is there a separate salt generator function used? Is it just a random generator? Does it need to be a ...
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1answer
142 views

Does salted password hashes expose users with blank passwords?

Traditionally, a 'salted' hash of the password is stored along with the salt so there is no plaintext in the database and still be able to authenticate the password. The salting process consists of ...
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2answers
167 views

BCrypt workfactor for salt?

From what I read here: How to securely hash passwords?, you're supposed to iterate the hashing. However in the implementation of BCrypt for .Net uses the workfactor (2^wf iterations) in the '...
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1answer
65 views

Recover SHA1-encoded email addresses

Say you have a list of SHA1 hashes which are all encoded with the same salt. All of these are email addresses and you know at least one combination of hash and email address. Is it possible to use a ...
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0answers
350 views

How do I combine a salt and hash for John The Ripper? [duplicate]

I found a password hash *61A2BD98DAD2A09749B6FC77A9578609D32518DD I found a salt somewhere else. How do I combine these to feed into John the Ripper? When I run John on the hash (minus the *) John ...
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1answer
86 views

Implementing SRP without storing the salt anywhere

I am attempting to use SRP to verify clients when they authenticate with a webserver, so that the password is never sent over the wire. Looking at the SRP procedure, when a client registers with the ...
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1answer
219 views

Difference in between salt and random padding in cryptography

I would like to know what is difference in between using salt and using "random padding" in cryptography. I am familiar with term salt when we use it with hashing. How does "random padding" differ ...
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3answers
350 views

How is a pepper used with salted passwords?

How is a pepper (a large constant number) used after a password has been salted with a salt by a hashing function such as bcrypt? From Sybex CISSP Official Study Guide, 8th Edition (2018): Adding ...
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1answer
115 views

Slow Hashing Without a Salt?

I'm trying to design a security scheme that involves a shared secret but isn't a traditional account password situation. The server would store a set of "keys", each of which has a blob of data ...
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4answers
407 views

Common format to send encrypted data + IV?

I have an app that receive data from third parties using various protocols: MQTT, HTTP, AMQP, ... Some clients cannot use TLS (iot devices without TLS support), so we need to find some compact and ...
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1answer
486 views

Hash a secret API key with a random salt instead of sending sending it alone in REST API

Say, I have an internal https API endpoint used only by me being the admin. In each each request I send a secret API key for authentication. And I'm fine with this solution. curl -x PUT ....... -...
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4answers
985 views

Securing hashes of short enumerated values

The system manages and stores sensitive data of short strings. Because the sensitive data is of an enumerated type with limited set of well known values, the attacker could easily iterate all the ...
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1answer
110 views

How to securely generate and store the salting for password hash? [duplicate]

Assume a client authenticates using the password, which includes hashing and salting. The hash values are stored in a remote database server. Questions: For the hash values stored in the database ...
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2answers
485 views

Generating salt for hash that occurs on server and client

Let's say I have an API call which is supposed to check if email address exists in the DB, without transmitting the actual email address. For that purpose, I've decided to store SHA256 hash of the ...
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1answer
8k views

How can I use openssl to decrypt AES-encrypted data using the key and initialization vector?

I am attempting to follow the example in this question: Where is the salt on the OpenSSL AES encryption? but I'm having some trouble decrypting using the key and initialization vector. When I ...
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1answer
464 views

Why has salt option been deprecated as of PHP 7.0.0?

http://php.net/manual/en/function.password-hash.php Is that less secured ? echo password_hash("rasmuslerdorf", PASSWORD_DEFAULT); => $2y$12$QjSH496pcT5CEbzjD/vtVeH03tfHKFy36d4J0Ltp3lRtee9HDxY3K ...
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3answers
173 views

Can one find the value of a “constant salt” if they can set the password and get the hash?

Saying we have an oracle that an attacker can use as many time as they want. The attacker can send a non-empty password to this Oracle. The Oracle hashes the password using sha256(password + pepper), ...
2
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1answer
317 views

How to store secret key used for hashing?

I am trying to figure out a secure way to store secret keys used in the hashing of social security numbers. The idea is for de-identification of research subjects yet still permitting follow-ups ...
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2answers
156 views

Can hash collisions be eliminated by hashing twice? [duplicate]

Suppose I have a file verified.txt that has a certain hash X. An attacker can form an impostor.txt that replicates the hash with different content, resulting in a collision for a given algorithm, and ...
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1answer
126 views

Using the user's GUID-id as a salt for Rfc2898DeriveBytes

I use the Rfc2898DeriveBytes for creating an AES key for protecting the user's data. For the salt value I would like to use the user's id, which is a guid. My understanding is, that the only drawback ...
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2answers
221 views

Does having a salted password hash make cracking an unsalted hash of the same password easier?

I've been asked to implement a system to prevent reusing passwords on the same account. The most secure way I know to do this is to compare hashes of the password + a known salt. bcrypt.hash(sha256(...
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1answer
3k views

bcrypt no need to store salt?

I'm confused with bcrypt, I would think I would need to store my salt, and then compare my plain text password + salt to the hashed password, however from documentation it does not look like storing ...
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1answer
163 views

Should I store my encrypted password's salt and initialization vector as clear text?

I'm encrypting some file with AES-256-CBC, and I'm planning to store the cipher text in a json file, with something like: { "data": "0123456789ABCDEF...", "salt": "00123ABCAABBCCDD...", "...
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1answer
320 views

Encrypted data embedded in JPG and Other file types

This is some data found near the end of a JPG file: 18{8uck3y3$} ! 18{b4063c521f76545d8c94e999dd63f445d8c01cfc} # 18{U2FsdGVkX19RJjdBbDB51ok1hkFXaB91NpZNoQjbVXYlMeMTaWRTdg==}? Other files on the ...
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7answers
13k views

Is it safe/wise to store a salt in the same field as the hashed password?

In using Argon2 for hashing passwords in my application, I've noticed it generates a string like this (e.g. for password "rabbit"): $argon2i$v=19$m=65536,t=3,p=1$YOtX2//7NoD/owm8RZ8llw==$...
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2answers
209 views

How to verify 2 hashed values with different salts originating from the same clear-text password?

I have a project where I need to do an account merge across two websites. Some percentage of users have accounts on both sites (same email address). Rather than just assume that two accounts with ...
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1answer
40 views

Store hashes for a finite set of strings that would be extremely time consuming to reverse via table lookup but also allow grouping

Lets say I have finite set of strings (lets say half a billion). There can never be any other strings I would need to store other than these half a billion strings. The strings may be repeated in my ...
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0answers
37 views

How to get desired output from salt? [closed]

If you wanted to get a specific output from php's $salt. function, how would you do this. By this I mean, If you know $salt."some_value" gives you desired_value, how do you find that some_value, if ...
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2answers
178 views

Web Service Authentication Using PBKDF2 and a Public Salt - Does the salt need to change on every request?

I have implemented PBKDF2 authentication for some web services. The client is given the following information, so they can duplicate the PBKDF2 function: the hashing algorithm (SHA256) a secret ...
39
votes
4answers
12k views

Is it safe to check password against the HIBP Pwned Passwords API during account registration?

User registers account on a web app. Passwords are salted and hashed. But is it safe to check the password against the HIBP Pwned Passwords API, before salting and hashing it? Of course the app uses ...
27
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1answer
8k views

How does the attacker know what algorithm and salt to use in a dictionary attack?

I am curious about password cracking methods like dictionary and brute force attacks. Nowadays passwords are stored as hashes and not plaintext on the server. Then how can the plaintext passwords in ...
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1answer
122 views

if salt stored in user, will it be possible to use brute force attack? [duplicate]

I had done a lot of research about this topic. Before Researchs I found that some people suggest that to hide salt is not important: https://crackstation.net/hashing-security.htm But also this ...
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3answers
496 views

Why do salts for hashing passwords need to be globally unique, not just system/site-unique?

I was reading an answer by Terry Chia to another question about the requirements for a salt, in which he/she (among others) specified that salts need to be globally unique, but don't go into any ...
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2answers
953 views

Is salting a hash more secure than encrypting it?

Assuming most-secure algorithms used for either, what I'd like to understand and get the answer for, is whether a salted hash is more secure than an encrypted hash? Although similar to this question ...
3
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1answer
284 views

Is appending a salt before hash generation enough

I have what I think is a securely generated salt/hashing mechanism for HMAC authentication based on SHA256 in place. However, I'm using the salt in, from what I can see, a fairly standard way of just ...
0
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1answer
477 views

Would it be considered good practice to make the salt for a password the hash of the user's username? [duplicate]

I heard it was good practice to have each user have a unique salt, when I'm hashing a user's password with a salt. My question is, can I make my salt a hash of the user's username? Ex. $username_hash ...