What Is Salting?

Salting is the practice of adding unique random data to a password before hashing it for storage. In password security, salting ensures that even if two users choose the same password, their stored password hashes will be different. That makes stolen credential databases harder to crack efficiently and reduces the value of precomputed attacks such as rainbow tables.

Salting is a basic part of secure password storage, but it works best when combined with a proper password hashing algorithm like Argon2, bcrypt, or scrypt. For related background, see what is hashing and what is mfa.

How salting works

Salting is part of the password storage process, not a replacement for hashing.

A unique salt is generated

When a user creates or changes a password, the application should generate a unique random salt for that password.

A properly designed system then:

• Creates a random salt
• Combines the salt with the password
• Hashes the result with a password hashing algorithm
• Stores the salt and resulting hash

The password itself should never be stored in plaintext.

The salt changes the hash output

Without salting, two users who pick the same password will end up with the same stored hash. That creates an obvious weakness because an attacker who steals the database can quickly identify matching passwords across accounts.

With salting:

• User A and User B can choose the same password
• Each user gets a different random salt
• Each stored hash comes out differently

This prevents attackers from looking at a database and instantly grouping all users with the same password.

The system verifies logins with the stored salt

When the user logs in later, the system does not decrypt the stored value. Instead, it:

• Retrieves the user’s stored salt
• Combines that salt with the submitted password
• Hashes the combination again using the same algorithm and settings
• Compares the result with the stored hash

If the values match, the login is accepted.

This is why the salt does not need to be hidden. Its job is uniqueness, not secrecy.

Why salting matters

Salting improves password storage by making offline cracking less efficient.

It stops identical-password matching

If a breached database contains unsalted hashes, matching hashes often reveal that multiple users share the same password. That gives attackers immediate insight into password reuse patterns.

Salting prevents that shortcut because the same password produces different stored outputs for different users.

It weakens rainbow table attacks

A rainbow table is a precomputed mapping of common passwords to their hash values. These tables are useful against unsalted hashes because the attacker can compare stolen hashes against known values quickly.

Salting breaks that efficiency. Because each password hash uses a different salt, the attacker would need separate precomputation for each unique salt. That makes rainbow tables far less practical.

It forces attackers to work account by account

When salts are unique, an attacker cannot crack one hash and automatically apply that result across every account with the same password hash. They have to work on each record more individually.

That does not make password cracking impossible, especially if users choose weak passwords. But it raises the cost significantly.

Salting is not enough on its own

Salting is necessary, but it is not the whole answer.

If a system salts passwords and then uses a fast general-purpose hash like SHA-256, the hashes may still be crackable at high speed with modern hardware. Best practice is to combine salting with a password hashing algorithm designed specifically for credential storage.

Common choices include:

• Argon2
• bcrypt
• scrypt

These algorithms are deliberately slower and more resource-intensive than general-purpose hashes, which makes brute-force cracking more expensive.

When you will encounter salting

You are most likely to encounter password salting in discussions about password storage, authentication security, and breach impact.

Common situations include:

• Application development: Developers need to store user passwords safely
• Security reviews: Auditors check whether password hashes are salted and properly hashed
• Incident response: Teams assess how hard stolen password databases will be to crack
• Identity platform migrations: Legacy systems may still use weak or outdated storage methods
• Compliance assessments: Organizations review whether credential handling meets current standards

If a company says passwords were “salted and hashed,” that is generally much better than storing plaintext passwords or unsalted hashes, though the exact security still depends on the hashing algorithm and configuration used.

Salting vs related terms

Salting vs hashing

Hashing turns input data into a fixed-length output. Salting adds unique random data before hashing so that identical passwords do not generate identical stored hashes.

Salting vs encryption

Encryption is reversible if you have the key. Password storage should generally rely on hashing, not encryption, because the system does not need to recover the original password.

Salting vs peppering

A pepper is an additional secret value used during password hashing, typically stored separately from the database. Unlike a salt, a pepper is meant to remain secret. Peppering can add defense in depth, but it does not replace salting.

Salting vs MFA

Salting protects stored password hashes if a database is stolen. MFA reduces the damage of a stolen password during login. They solve different problems and work well together.

For stronger account protection overall, users should also use unique passwords managed with a password manager such as Try 1Password →, and endpoints that store or process credentials should be protected with reputable security software like Get Malwarebytes →.

Common mistakes with salting

Salting is widely understood, but implementation mistakes still happen.

Reusing the same salt everywhere

A salt should be unique per password. Using one global salt across all accounts reduces the benefit significantly.

Using weak random generation

Salts should be generated with a cryptographically secure random source. Predictable salts make attacks easier.

Pairing salts with weak hashing

Salting alone does not compensate for the use of fast, outdated, or inappropriate hash functions.

Treating salting as optional

Modern password storage should assume salting by default. Most modern identity frameworks already do this correctly, but older custom systems may not.

Final takeaway

Salting is the practice of adding unique random data to a password before hashing it. Its purpose is to make identical passwords produce different stored hashes and to reduce the effectiveness of rainbow tables and large-scale cracking shortcuts.

It is a foundational password security control, but it works best when paired with strong password hashing algorithms like Argon2, bcrypt, or scrypt, plus broader protections such as MFA and unique passwords. If you store user passwords at all, salting should be standard, not optional.