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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4
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2answers
3k views

Should I use urandom() or openssl_random_pseudo_bytes()?

I am developing a site in PHP 5.4. Which function is better to use to generate a random salt for password security? $salt = sha1(openssl_random_pseudo_bytes(23)); or $seed = ''; $a = ...
3
votes
2answers
178 views

Are credit card number look ups more secure with a hash function than with a deterministic encryption algorithm?

I understand PCI DSS 3.0 allows hashes of cardnumbers to be stored separately from encrypted values, but I'm startled at the efficiency of tools like hashcat in discovering card numbers from hashed ...
85
votes
6answers
29k views

Password Hashing add salt + pepper or is salt enough?

Please Note: I'm aware that the proper method for secure password storage hashing is either scrypt or bcrypt. This question isn't for implementation in actual software, it's for my own understanding. ...
6
votes
3answers
211 views

Image file as password alternative

I seek guidance on interesting issue. Recently I've been searching for password alternatives, not because of the security, but to be more user-friendly. In one of my projects user receives 128 bits ...
0
votes
1answer
116 views

Publicly Available API + Sensitive ID/Key Transmission Over HTTP

I've run into a predicament... I'm developing a mobile application that utilizes a server for various things. One portion is that it stores an id/key pair related to accessing and processing ...
22
votes
7answers
6k views

Why don't people hash and salt usernames before storing them

Everyone knows that if they have a system that requires a password to log in, they should be storing a hashed & salted copy of the required password, rather than the password in plaintext. What I ...
12
votes
6answers
2k views

Do salts have to be random, or just unique and unknown?

First of all, my motive is to avoid storing the salt in the database as plain text. As far as this question is concerned, the salt is not stored in the database. After discussion in comments and in ...
31
votes
7answers
9k views

Is salting a hash really as secure as common knowledge implies?

(I did search on this topic, but I found no complete question/answer that addressed it, or even good portions of questions that might be relevant.) I'm implementing a salt function for user passwords ...
4
votes
1answer
555 views

Is it a good idea to use two salts? [duplicate]

Is it a good idea to use two salts? This is implying that one would be unique to the user, and one would be unique to the server, using Bcrypt of course. So for example, if you're using Golang as ...
1
vote
2answers
125 views

Is bruteforcing the last character of a salt a good idea?

Would it be a good idea security-wise to store salts with their last character removed, and then bruteforce the last character to further the amount of time it would take to create rainbow tables and ...
1
vote
2answers
56 views

Hashing password with salt [duplicate]

I read from wiki: The attacker has access to both the hashed password and the salt, so when running the dictionary attack, the attacker can simply use the known salt when attempting to crack the ...
14
votes
6answers
2k views

What are the differences between an encryption seed and salt?

Today I had a hard time explaining the difference to a friend. I know seeds are used when generating "random" strings. And salts are used when providing different outcomes to a hash. What is a ...
1
vote
3answers
80 views

How to compare passwords with duplicate password

On Steam, the gaming client, I have this habit of creating multiple "smurf" accounts. I have a randomly-generated, unique password, and I decided to use the same password for all of my multiple ...
2
votes
1answer
105 views

Crackstation “Secure Salted Password” Java example - is it really secure?

I'm making an auth service so I've been looking for some good Java/Groovy implementations of password + salt hashing. I've found this article on crackstation along with a code example and decided to ...
3
votes
5answers
261 views

Are all unsalted password hashes inherently insecure?

Maybe I'm missing something obvious... Are all passwords stored in common, unsalted hash algorithms able to be attacked via rainbow tables?
1
vote
1answer
58 views

Storing salt and hashed password [duplicate]

Is there a benefit to storing salt appended to hashed password in a single column of a table verses storing salt and hashed password in different columns of the table. The OWASP guide here ...
216
votes
7answers
30k views

How to store salt?

Nowadays, if we expect to store user password securely, we need at least do the following thing $pwd=hash(hash($password) + salt) then store $pwd in your system instead of the real password. I have ...
1
vote
2answers
46 views

One-way function for data synchronisation

I have to synchronise small sets of data between two or more systems over an insecure network. First I have to check that the other system has the same unique identification information for the data ...
11
votes
2answers
679 views

How can I find out the password hashing schemes used by the specific Unix accounts I log in to?

Every day I ssh in to 3 or 4 independent Unix accounts. I have been regarding them as more or less "equivalently secure" on the grounds that I'm using ssh, but after learning of how much variety ...
0
votes
2answers
69 views

Is it safe to use a derivative of a password as a salt

I know for a fact that salts are an important part of storing a password securely in a database. Most people store the password hash, and the salt that was used for it. This, I have learned, isn't ...
20
votes
5answers
3k views

Does too long a salt reduce the security of a stored password hash?

Suppose we have passwords that are statistically 7-8 characters long. Is appending a 200 character long salt less secure than a 5 character salt, because of the similar hash function inputs? I was ...
0
votes
2answers
73 views

Separate database column for salt

Is it advisable to store the salt in a separate database column or should we concatenate it together with the password? Is there any difference? I have come across implementations of both types. ...
0
votes
0answers
52 views

Suggestion of encrypt method for short fixed size result

I'm searching for a encrypt method that receives an int variable and outputs exactly 11 hexadecimal digits. I'm starting on a existing application, that already has a database of more than 130.000 ...
0
votes
3answers
102 views

Creating user and safely sending password

Assuming I currently use a safe way to salt-challenge-response-authentication-method, passwords are stored secured and all. I now question myself - how do users set the password? Meaning, they enter ...
2
votes
2answers
455 views

PBKDF2: can the salt be known from the hash?

I understand that some KDFs bundle the salt with the output, such as bcrypt (modular crypt format). In PKCS5_PBKDF2_HMAC (specifically, looking at OpenSSL implementation) with a single iteration, is ...
1
vote
0answers
85 views

Why do we need salt and RFC in generating AES encrypted message

I'm not very familiar with encryption and new to this, I'm just learning it right now by code review of one of the class we have in an application to encrypt a password using AES. Would anyone explain ...
135
votes
8answers
16k views

Why are salted hashes more secure?

I know there are many discussions on salted hashes, and I understand that the purpose is to make it impossible to build a rainbow table of all possible hashes (generally up to 7 characters). My ...
8
votes
6answers
999 views

Is it useful to protect hashed password with encryption?

Imagine that I am hashing the users' passwords with a random, long enough, salt, using key stretching, and a secure hash. Would it be more secure to finally encrypt the hash with a symmetric key?
3
votes
1answer
349 views

Perfectly Robust Hashing Scheme, or Completely Over-Engineered?

This is going to get long, so prepare. Basis of the question is, Do all these steps improve security, or am I completely overthinking the problem? Are my assumptions/thought process valid? We all ...
5
votes
2answers
769 views

Can the IV + Salt be the same?

During my encryption app i've got the password creation bit: PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 10000, keyLength); and later on the actual encryption part: ...
8
votes
5answers
2k views

Should I remotely store my salt? [duplicate]

When users register on my site, I want to store their username and hashed password in my database. When I hash that password, I'm going to salt it using PHP. The issue is, I don't want to store the ...
5
votes
2answers
696 views

Authentication: Username (email) and password hashed together in one database field

I am currently developping a platform with a PHP framework for our client. The head of the client's IT department wants us to handle authentication with one database field containing ...
1
vote
2answers
156 views

Is it a good idea to use the user's username as a salt when hashing a password like hash(username_str + password_str)?

I'm helping my friend with hashing his passwords, and I've a question - Should he use one secret string as salt for hashing or is it better to have each user its own salt for hashing? Consider these ...
-2
votes
3answers
199 views

My friend hashes passwords with SHA512 algorithm without salt. How do I convince him that he needs to add salt?

Today I discovered something incredibly stupid - my friend hashes user passwords with sha512 algorithm without a salt. I immediately raised this issue to him but he said he wants to see anyone crack a ...
2
votes
1answer
135 views

How to autenticate properly in Java

I have to write some login module for Java EE application. Previously i was using JBoss security - provided login and password, called HttpServletRequest with login method and JBoss security did the ...
3
votes
3answers
522 views

Accepting other similar passwords when storing a salted, hashed password

If a website stores passwords as a salted hash, is it reasonable to accept similar passwords as correct? For example, given the password stackexchange, does it dramatically decrease security if the ...
2
votes
1answer
336 views

MySQL Authentication Hash Cracking

I'm currently conducting research regarding MySQL server remote authentication. I've captured unencrypted, uncompressed authentication packets between the client and the server where the username is ...
1
vote
2answers
145 views

Search on hashed data

We have a request to encrypt customer personal data (e-mail, address etc.) We use MySQL which does not have any TDE like MS SQL or Oracle. So along with encrypting data we need to preserve ...
4
votes
2answers
229 views

Is there a strong reason to salt and hash passwords when password reuse is not an issue?

I am dealing with a system (in development) that uses randomly generated (not user provided), unique, strings to authenticate services that will consuming an API. Right now, these strings are stored ...
4
votes
1answer
154 views

Using random number to salt passwords

in a project I have, I'm salting passwords with 3 salts at the moment... Static salt - hard-coded into the source-code. Randomly generated salt (using a function designed for generating password ...
13
votes
2answers
856 views

How Does A Random Salt Work? [duplicate]

I don't understand how using a random salt for hashing passwords can work. Perhaps random salt refers to something other than hashing passwords? Here is my thought process: The salt is used to add ...
-2
votes
1answer
81 views

Salt and password [closed]

Reading the doc for setting the password, the command is : python -c "import crypt; print crypt.crypt('password', '\$6\$SALTsalt')" SALTsalt is the 8-character crpytographic salt. Valid characters in ...
0
votes
1answer
69 views

Good way to make a secure token for logged out users

I work for a firm that has a marketplace on the web. We want to make a link with a token that stops an ad on the marketplace without the user being logged in. Someone suggested that we make a token ...
2
votes
4answers
728 views

Using last characters of hash as salt [duplicate]

In a recent discussion somebody mentioned the following hashing scheme: passHash = sha256(password) saltedHash = sha256(passHash+passHash.substr(-10) finalHash = sha256(secret+saltedHash) The ...
3
votes
2answers
164 views

Search on encrypted data of multiple users

I want to implement a search over encrypted data. I found a blogpost, which explains 3 methods. One method is to use deterministic encryption, which I'm trying to implement. But my use case is a ...
0
votes
1answer
128 views

Save password on user-side for autologin

If a user wants to login to a system/server, it's recommended to have the hashed&salted password saved in a database, along with its salt. So the user wants to login, types in the password, ...
1
vote
2answers
106 views

Is it unsafe to hash one password with more than one salt?

I'm asking my question here since I was not able to find an answer anywhere. I have written a piece of software which stores pretty delicate passwords. I have used BCrypt as hashing algorithm with an ...
-1
votes
2answers
106 views

How does salting increase security? [duplicate]

I'm currently going through a course on software security. I've recently been introduced to the idea of password salting, where a random value is concatenated to a password prior to being hashed and ...
71
votes
8answers
9k views

Convincing my manager to use salts

My manager says we don't need to salt our passwords because people are not likely to use the same password because they all have different native languages, in addition to the websites they are active ...
0
votes
3answers
61 views

How to secure Password and Salt on a deployed application

I have a question regarding one step of protection more than salt/hash. I work on an application that is distributed to many clients and then deployed on their networks. If I set a password on one ...