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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8
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5answers
436 views

Find matching phone numbers without actually knowing them

We have a mobile app that, given two users, needs to let them see what common contacts they have based on their phone numbers. How can we do this in a cryptographically secure way and respecting the ...
1
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1answer
56 views

Secure WebApp authentication

I know there are many questions about hashing passwords on the client side out there, but none of them, which I found, address my use case. My app will be end-to-end-encrypted and it is not an option ...
0
votes
1answer
26 views

AES-CTR with PBKDF2 for IV for file archiving at server. Is this ok?

I have tried to grasp enough of encryption/hashing to be able to implement a secure storage for files, server side. Once I have it down to reasonably safe I'll go over it with an expert. There is no ...
116
votes
6answers
45k 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. ...
3
votes
4answers
136 views

Is knowing the salt a problem?

I understand that adding a salt would thwart the use of rainbow tables. I don't understand the time it would take to create a rainbow table for a certain salt and of course this is dependent on the ...
3
votes
1answer
62 views

Is appending plaintext to salt equally safe as appending salt to plaintext

Is using hash(salt, plaintext) equally secure as using hash(plaintext, salt), i.e. can the plain text be appended to salt in place of appending salt to the plain text. Why or Why not? What kind of ...
10
votes
2answers
12k views

How weak is MD5 as a password hashing function ?

A professor told us today, that MD5 is weak. I understand his chain of thought but pointed out, that IMHO MD5 is a good way to go if you would use a long (even really long) dynamic salts and static ...
0
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1answer
69 views

Checking a salted hash against known password?

I've created a mysql dump of my users and passwords and awked them into a presentable form: Passwords: ...
290
votes
8answers
53k 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 ...
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votes
2answers
56 views

Is there a reason to salt instead of enxrypting data? [duplicate]

Is it more secure to: a) Take a password, salt it, then hash it. b) Take a password, hash it, then encrypt it(Using a symmetric algorithm with a large key)
166
votes
8answers
34k views

Why are salted hashes more secure for password storage?

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 ...
0
votes
2answers
127 views

Can we store sensitive client information with the admins without them(admins) identifying it?

I am trying to design a pairing application for my university this valentine. How is it supposed to work, you ask?? The clients will submit preferences specifically names to the server and after some ...
42
votes
12answers
10k views

Is there any real value in hashing/salting passwords?

I look after a system which holds a lot of "low grade" information, nothing financial but name/address/email etc. Someone has suggested that we up the security from the current in house password ...
0
votes
3answers
75 views

How to use password salt the right way [duplicate]

I understand the basic idea of password salts. You generate a 'random' string of data prepend this data to a user password store password and salt (salt maybe even in 'clear' form) Like in the ...
4
votes
3answers
1k views

Determine hashing algorithm only with known input and output

Given the input: test A system generates the following output hash: 0x001F41B6A0534D3B851D69EFE6237F550100000010D5F4FC65E64BCFDBF2590212E4411C44942C6C734C00ACFE13B958DCAB3614 I do not know ...
3
votes
2answers
140 views

What is the etymology of “Salt” in relation to password storage?

Simple question: When talking about appending a random string to a password before hashing in order to defend against dictionary attacks, we call it a salt. Why do we call it a salt?
4
votes
1answer
112 views

How unique should I make my SSID?

Some say that a 32-character random string is a good idea for SSID names: Treat your WiFi network name as you would a password. Make it complex and avoid using any whole words. Maximum length for ...
3
votes
2answers
197 views

Hashing password multiple times with different random salts

I have read a lot of answers about this topic like: https://programmers.stackexchange.com/questions/115406/is-it-more-secure-to-hash-a-password-multiple-times. ...
0
votes
1answer
39 views

Salt generation for stream cypher

Sorry if this is an elementary question but I could not find a direct answer. For end-to-end encryption of messages that wait temporarily on a server and where the sizes can vary from just a few ...
6
votes
1answer
71 views

Using AES with same salt / IV - required for pattern matching algorithm

I need to securely encrypt data we are storing, but for each client I need the same plaintext to encrypt into the same cypher text. The reason for this is the data is still required for a pattern ...
-1
votes
2answers
59 views

How secure is a hash + reverse(hash)?

From what I know there is a method called salt added to hashes in order to prevent attackers from using pre-computed hashes. As long as the attacker can find a static salt in reverse hashing and do a ...
9
votes
3answers
6k views

I don't see how “-salt” in the openssl command line tool enhances security at all

I do this to encrypt a single file: openssl aes-256-cbc -a -salt -in file.txt -out file.enc and then type in some regular plaintext password. I do not understand how -salt enhances the security of ...
31
votes
4answers
6k views

What should be used as a salt?

I always hear that it is best to use salts on top of stored passwords, which then somehow gets concatenated and hashed afterwards. But I don't know what to use as a the salt. What would be a good ...
0
votes
3answers
103 views

Is it OK to reuse the same SALT key across multiple deployments?

We are building a base application that needs to encrypt SSN, DOB, etc... The application is deployed to many customers. Is it "OK" to use the same SALT key for the AES encryption/decryption ?
0
votes
1answer
167 views

How can I detect if hashes are salted? [duplicate]

Is it possible to detect hash function of a hash if I don't have access to PHP code? I know that if a hash is some kind of MD5, but I don't know if there is salt etc.
3
votes
1answer
65 views

Does salt increase security if there is only a single hashed password?

Say there is only a single hashed password in the passwords file. If it was salted, would that make it more secure? My logic is: Yes because SALT helps protect against rainbow tables and dictionary ...
2
votes
1answer
156 views

Use salt as identifier for crypted session id in database based authentication system for webapp

I have written a database-based authentication framework for webapps I am planning to program in the future. The framework is implemented by using the plpgsql-language of a PostgreSQL-Database and ...
-2
votes
1answer
109 views

How MD5 and salt algorithms come into play if the attacker uses curl?

When the user logs into any site, they supply a username ('user01') and password ('password123') into a form then submit. The user has no idea what their hashed password value is that is stored in the ...
7
votes
1answer
114 views

Forcing new password with zero-knowledge proof authentications

Let's say a ZKP (e.g. SRP6a) is used, for password verification. Let's say I need to force a user to change their password (so I have the salt and the verifier for the current password). For this, ...
5
votes
1answer
95 views

Salting/Hashing a password

I don't have a security background, so I'm not sure on the best approach for this, I'm developing an android app which users will need to login to (all local). I'm going to store the password in a ...
3
votes
1answer
51 views

secure user authertication

Here : Help understanding basic user authentication with salts and hashing They explain it pretty well, but i'm still struggling to understand this one part... Now, when a user comes to log in ...
1
vote
1answer
162 views

best practices for storing retrievable passwords

I am trying to build a NMS (network management system) and I am required to store passwords for 3rd party databases, devices and servers that are being managed (not user passwords). These passwords ...
-1
votes
1answer
69 views

Finding the cryptographic hashing algorithm, given the plain text and the corresponding salted hash [duplicate]

I have a salted hash (say about, 110 characters long) and the corresponding plain text that I used for hashing. As the title says, is it possible to do find the algorithm via crypt-analysis? What is ...
0
votes
1answer
58 views

Store Hash and/or Encryption salts in database [duplicate]

I am doing a custom login for practice purposes, and i am wondering what would be the logical way to save the hashed password and the salts. Salt/Hash operations are using Rfc2898DeriveBytes class. ...
2
votes
2answers
1k views

Is it possible to salt the SHA1 or SHA256 hash function of OpenSSL?

I would like to salt the hash function of OpenSSL external, so that I can assign a salt on my own. Is that possible or is the hash function of OpenSSL alsways internal "salted"?
3
votes
1answer
168 views

Challenge: How to find the secret key in homebrew MAC/keyed hash: sha1(key + cookie)?

I am trying to solve a security challenge on a website. Basically, the website computes sha1(key + cookie) to sign a cookie so that the user can't change it himself, and to accomplish the goal you ...
3
votes
1answer
2k views

Correct way to generate password salts in PHP 5.3 on Linux given my constraints?

In examining our database storage of hashed passwords with salts, I note a high rate of salt collisions, i.e., there are far too many cases where two table rows have the same salt stored. One ...
13
votes
1answer
12k views

Where is the salt on the OpenSSL AES encryption?

I'm interested in knowing how and where OpenSSL inserts the generated salt on an AES encrypted data. Why? Im encrypting data in Java classes and need to guarantee that I can use OpenSSL to decrypt ...
17
votes
1answer
2k views

Password hashing : Using 2 salts [duplicate]

I'm developing an authentication service. I know the practice of generating a unique salt per user, stored in the DB with the hashed password, to prevent rainbow tables attacks. I just had the idea ...
0
votes
1answer
175 views

Is it possible to find out the salt of a MD5 hash?

I want to know whether it is possible to find out the salt of a MD5 hash? For instance we've got two MD5 hashes helloworld -> fc5e038d38a57032085441e7fe7010b0 goodbyeworld -> ...
2
votes
1answer
128 views

OS login password: How does it work?

I am making an application to create a password for a user. I am a bit baffled over how it all works though. Namely I want to be sure that my application will store the correct hash so the user can ...
2
votes
2answers
686 views

Determine salt length from hash

I am writing a basic Unix password cracker in Python that would work for MD5, SHA-1 and SHA512. I know that the salt in MD5 correspond to the 2 first chars of the encrypted password, and thus I ...
4
votes
1answer
159 views

Protect password/authenticating during transit over (insecure) TCP socket for a game

Background I am designing a multi-player game with a single server that handles multiple worlds. Each player logs into the server initially before requesting which world to join. The server has a ...
-3
votes
1answer
69 views

How to find an encryption algorithm between two hexadecimal numbers? [closed]

I have several numbers that are generated by a server. They are 16 digits long and are hexadecimal. I have no idea whether or not any salting or hashing techniques were used. Can I find the encryption ...
2
votes
1answer
74 views

Do password derived encryption keys need to be salted?

If I have a database where I store users' sensitive information, and encrypt that information, do I need to do something like PBKDF2(password,salt,10^5) for the encryption key as well as the hash?
2
votes
1answer
291 views

Reverse engineering of a global hash salt from known plaintext and hash

First of all i'm not asking what is a hash, or something else. I will try to explain what i'm searching clearly: Let's say I have a dump of a database, all the passwords of this database are hashed, ...
2
votes
3answers
190 views

How does a hash which contains algorithm to choose can be secure?

I was thinking about creating my own hash+salt function, something like sha1(password + md5(login)), then I read here (part 4) that creating it's own hash+salt function is a bad idea, because if the ...
3
votes
2answers
181 views

Guid salt - string vs bytes[]

Recently I got into passwords hashing (SHA256, HMAC-SHA1, PBKDF2, etc.) and one "statement" I've been reading over and over again, stuck in my mind and I can not find a satisfying answer. "When we ...
3
votes
3answers
78 views

where to store the salt for “crypto_pwhash” in a web application with no local storage

I am developing a web application which stores encrypted data on a server. I want to derive the encryption key as well as the login key from a single user password, so I want to use libsodiums ...
5
votes
5answers
2k views

Salted password + hash - is it really useful? [duplicate]

I am new to the topic and wanted to know the concept of having salted hashes before going down to the technical details. From what I have understand password - plaintext hash password - plaintext ...