What is hashing and salting

To mitigate the damage that a hash table or a dictionary attack could do, we salt the passwords. According to OWASP Guidelines , a salt is a value generated by a cryptographically secure function that is added to the input of hash functions to create unique hashes for every input, regardless of the input not being unique. A salt makes a hash function look non-deterministic, which is good as we don't want to reveal duplicate passwords through our hashing.

We can salt that password by either appending or prepending the salt to it. For example: farmM0Of1nd1ngn3m0 or f1nd1ngn3m0farmM0O are valid salted passwords. Once the salt is added, we can then hash it. Let's see this in action:. Hash SHA : ed35c6ebf7ea02fd98ab88d92ccf4e48a4bfccb90aec. Hash SHA : 07 dbb6edadde4bf1a94a7b3dd26ff3c This demonstrates the importance of using unique salts. Both salted passwords would hash to the same value.

But, if we choose another salt for the same password, we get two unique and longer passwords that hash to a different value.

Let's visualize this through an example:. Alice and Bob decide to use both the same password, farmM0O. For Alice, we'll use f1nd1ngn3m0 again as the salt. However, for Bob, we'll use f1nd1ngd0ry as the salt:.

Hash SHA : 11 ceb6c1bfbe60a0aa2a2f8c0a0ceed92fea5bfdc8f6. Different users, same password. Different salts, different hashes. If someone looked at the full list of password hashes, no one would be able to tell that Alice and Bob both use the same password.

Each unique salt extends the password farmM0O and transforms it into a unique password. Additionally, when a user changes their password, the service should also generate a new salt. In practice, we store the salt in cleartext along with the hash in our database. We would store the salt f1nd1ngn3m0 , the hash 07 dbb6edadde4bf1a94a7b3dd26ff3c , and the username together so that when the user logs in, we can lookup the username, append the salt to the provided password, hash it, and then verify if the stored hash matches the computed hash.

Now we can see why it is very important that each input is salted with unique random data. When the salt is unique for each hash, we inconvenience the attacker by now having to compute a hash table for each user hash. This creates a big bottleneck for the attacker.

Ideally, we want the salt to be truly random and unpredictable to bring the attacker to a halt. While the attacker may be able to crack one password, cracking all passwords will be unfeasible. Regardless, when a company experiences a data breach, it is impossible to determine which passwords could have been cracked and therefore all passwords must be considered compromised.

A request to all users to change their passwords should be issued by the company right away. Upon password change, a new salt should be generated for each user as well. Is f1nd1ngn3m0 a good salt? When we are adding salts to passwords, we need to add salts that are cryptographically strong and credential-specific. A system-wide salt is pointless to mitigate attacks; it would just make passwords longer. A system-wide salt also easily allows an attacker to keep using hash tables.

We should hash and salt each password created for a user. That is, we should generate a unique salt upon creation of each stored credential not just per user or system-wide. That includes passwords created during registration or as the result of a password reset. If the user eventually cycles over the same password, we don't want to give away that the password has already been used. Cryptographically strong or strong cryptography define a cryptographic system that is highly resistant to cryptanalysis , which are efforts to decipher the secret patterns of a system.

Showing that a cryptographic scheme is resistant to attacks is a complex process that requires a lot of time, extensive testing, reviews, and community engagement. Due to this complexity, security experts recommend that you don't roll your own cryptography.

Though even if someone knows your salt cannot hack your information as hashing is itself very secure. Solution: System. Encryption Encryption is the process of converting the information from one form to another using an encryption key. Encryption is always done with the intention of recovering the original information back.

Encryption is a two-way process. It allows us to encrypt as well as decrypt the information. Hashing Hashing is the process of converting information from one form to another, but in case of hashing, information is not recoverable.

Hashing is always done with the intention when we do not want to get the original data back. Salting loses its effectiveness if it is done incorrectly. If salts are reused for each hashed password, and the salt is discovered, it makes it much simpler to figure out each password in the database.

Using the same salt also means that anyone with the same password will have the same hash. Instead, a number of functions have been designed with specific features that help to boost security. Despite its youth, so far it has held its own in a number of research papers that have probed it for weaknesses. Argon2 is more flexible than the other password hashing algorithms and can be implemented in a number of different ways. Designed in , scrypt uses a large, yet adjustable amount of memory in its computations.

Its adjustable nature means that it can still be resistant to attacks even as computing power grows over time. It was one of the most commonly relied upon algorithms used in password hashing for many years, but it is now more vulnerable to field-programmable gate arrays FPGAs.

This is why Argon2 is often preferred in newer implementations. This key derivation function was developed to replace PBKDF1, which had a shorter and less secure key length. NIST guidelines from still recommend PKFD2 for hashing passwords, but Argon2 addresses some of its security issues and can be a better option in many situations.

While each of these processes is related, they each serve a different purpose. Encryption is the process of encoding information to protect it. When data is encrypted, it can only be decrypted and accessed by those who have the right key. Encryption algorithms are reversible, which gives us a way to keep our data away from attackers, but still be able to access it when we need it. It is used extensively to keep us safe online, performing a crucial role in many of our security protocols that keep our data secure when it is stored and in transit.

In contrast, hashing is a one-way process. Cryptographic hash functions have a number of unique properties that allow us to prove the authenticity and integrity of data , such as through digital signatures and message authentication codes.

Specific types of cryptographic hash functions are also used to store our passwords. While password hashing does make life more difficult for hackers, it can still be circumvented. This is where salting comes in. Salting adds extra data to passwords before they are hashed , which makes attacks more time-consuming and resource-heavy.

If salts and passwords are used correctly, they make hash tables and rainbow tables impractical means of attack. Together, encryption, hashing and salting are all important aspects of keeping us safe online. This site uses Akismet to reduce spam. Learn how your comment data is processed. Comparitech uses cookies. More info. Menu Close. We are funded by our readers and we may receive a commission when you make purchases using the links on our site. The unique properties of encryption, hashing and salting are vital for keeping our online world secure.

In this article, we'll look at each of them in depth in order to understand what these processes are and how they are used. December 21, What is encryption? See also: Common encryption types explained Common encryption algorithms Caesar cipher — This is a simple code that involves each letter being shifted a fixed number of places.

AES — The Advanced Encryption Standard is a complex symmetric-key algorithm that secures a significant part of our modern communications. It involves a number of sophisticated steps and is often used to encrypt data in TLS, messaging apps, at rest and in many other situations. We take a deeper dive in to AES encryption here. We have an in-depth guide to RSA encryption here.

As a public-key algorithm, it can be applied in similar situations to RSA, although it is less-commonly implemented due to some security issues. What is hashing? Hash functions have several different properties that make them useful: They are one-way functions — This means that there is no practical way to figure out what the original input was from a given hash value.

For practical purposes, hash values can be considered unique. The same input always delivers the same result — Every time you put the same information into a given hash function, it will always deliver the same output.

Even the slightest change gives a completely different result — If even a single character is altered, the hash value will be vastly different.

What are hashes used for? Common cryptographic hash functions MD5 —This is a hash function that was first published in by Ron Rivest. It is now deemed insecure and should not be used for cryptographic purposes.