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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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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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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
40 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
110 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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170 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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105 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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44 views

Add a secret key to Bcrypt ? [duplicate]

I'm a newbie with Bcrypt, after reading their npm presentation, I have seen that they don't provide key secrete feature. I wonder if it's possible to create a key secrete for Bcrypt as we would make ...
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296 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
299 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
969 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
105 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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257 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
4k 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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271 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
142 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), ...
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1answer
221 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
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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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103 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
176 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
1k 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
129 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
247 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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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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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
38 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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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
151 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 ...
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4answers
11k 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 ...
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1answer
7k 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
107 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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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
682 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 ...
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1answer
234 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 ...
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1answer
471 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 ...
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1answer
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Hash, salt and best practices [duplicate]

Reading about hashing, salt and pepper, I can't get my head around the following scenario: If there's a web application and you register on that site, should the password be hashed on the client or ...
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1answer
643 views

Does storing Base64 encoding of scrypt password hash make it more vulnerable?

Scrypt produces a binary hash of a password. Instead of storing it as bytes directly, we are considering to store the Base64 encoding of this string. Would that make the password hash more vulnerable ...
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1answer
620 views

Scrambling a salted password before hashing. Good idea or unnecessary?

I'm updating a legacy classic ASP site and I need to store passwords, so naturally I'm being a bit over cautious about how to go about this given the limitations of Classic ASP. I'm using both a salt ...
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44 views

Password Hashing [duplicate]

I am currently securing the password in PHP using hashing + salt. Before that I only used hashing but recently someone recommended using salts. My previous code: $password=hash('sha512',$...
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3answers
379 views

Solution to calculate and store a hash salt in an open source application?

I was watching this video about how NOT to store a password. I also read this question which is very similar. My question is slightly different in the fact that I'm writing an open source security ...
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1answer
785 views

How find the hash creation method knowing password, salt, and resulting hash?

If I know the password, the salt (supposed salt actually) and the output hash (sha1 format). How can I find the hash creation method ? I tried basic stuff like sha1(salt+password) sha1(...
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1answer
676 views

Using MD5 as salt

I know that MD5 is a poor choice for hashing passwords, but its not my ideia. Imagine that we would use the username as a salting mechanism, wich is also bad idea, but just for an example. First, we ...
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1answer
78 views

Does changing the scrypt salt have security implications?

I'm using scrypt to stretch a user-supplied password for use as an AES encryption key. The data that's being encrypted with the AES encryption never changes. I'm aware that if the user changes the ...
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2answers
231 views

Is mixing password hash and salt in the same database field more secure?

I am storing in my database the user password hash and salt. I would like to know if putting together hash and salt in the same field is adding complexity to a potential hacker who had access to the ...
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1answer
292 views

Is my authentication strategy secured?

I want to implement an authentication system by following good practices, i want it as simple as possible and secured (im not going to implement some magic hashing function or something to feel a hero....
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1answer
105 views

Does the length of Salt data influence how hard or easy it would be to crack/match a hashed password?

Does any guidelines or best practices exist when it come to choose the length of the Salt data. Does it matter in the effort a hack has to put to match the dictionary (or rainbow) table with the ...
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3answers
102 views

Are Salt strings stored by application? [duplicate]

1) As storing passwords in plain text in databases are not secure and so is not a good practice. password stored in db = "abcde" (plain text) 2) To avoid this, passwords are stored after being hashed ...
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86 views

Salting the same value many times

If someone were to hash the same value with a different salt many times, would it be possible to find the original value?
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2answers
594 views

How does authentication work if the password provides a different salt on every login?

How does an application authenticate a users password if every time he provides his password to access his account the password provides a different salt?
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1answer
784 views

Append or prepend a salt to a password? [duplicate]

Does it matter how I add a salt to a password in my application: by appending it or by prepending? # 1 res = sha256(salt + password) # 2 res2 = sha256(password + salt) I've been told that the 2nd ...
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3answers
65 views

Store a Cryptographic Hash with look-up capability

I want to be able to store the hash of a piece of text in a database and then allow a third-party to confirm its existence if they know the original text. I do not want to store the original text, ...