---
url: 'https://www.corbado.com/glossary/password-hashing'
title: 'Password Hashing'
description: 'Explore the method and role of password hashing in cybersecurity, ensuring the safety of user data through one-way hashing algorithms.'
lang: 'en'
keywords: 'password hashing'
---

# Password Hashing

## What is Password Hashing?

**Password hashing** is a cybersecurity technique used to transform a plaintext password
into a unique, fixed-size string of characters known as a password hash. This process,
performed by a hashing algorithm, ensures that even if data breaches occur, the actual
passwords remain concealed from attackers.

Password hashing is a one-way function, meaning it is computationally impossible to
reverse the process and retrieve the original password from the hash. When a user logs in,
the system hashes the entered password and compares it to the stored hashed password. If
they match, access is granted. This method is important for safeguarding user information
against theft and misuse, especially considering the increasing frequency of cyberattacks
and data breaches.

While password hashing enhances the secure storing of passwords, it should be used in
conjunction with other security measures, like encryption and multi-factor authentication,
for comprehensive protection.

> - **Password hashing** transforms plaintext passwords into unique, secure hashes,
>   protecting them from unauthorized access.
> - It's a one-way process, making it nearly impossible to revert to the original password
>   from the hash.
> - Hashing algorithms like SHA-256 and Argon2id are recommended for their robustness
>   against common brute-force attacks.
> - Additional security measures like salting and peppering can further enhance the security
>   of hashed passwords, making it harder to crack them through dictionary attacks or
>   rainbow tables.

---

### Enhancing Security with Password Hashing

The transition from storing passwords in plaintext to using hashed passwords marks a
significant advancement in digital security. Password hashing is essential for any system
that uses password-based user authentication, as it minimizes the risk associated with
storing sensitive data. Here's how password hashing contributes to a secure digital
environment:

- **Mitigating Data Breach Impact:** Even if attackers gain access to a database, hashed
  passwords do not directly expose user credentials.
- **Preventing Password Reuse Attacks:** Hashing makes it difficult for attackers to
  [exploit](https://www.corbado.com/glossary/exploit) the common practice of password reuse across multiple
  platforms, since the hashes are different on different platforms if combined with
  salting and peppering.

### Advanced Techniques: Salting and Peppering

To combat sophisticated attack strategies like dictionary attacks and rainbow tables,
security experts recommend salting and peppering passwords before hashing them.

- Salting adds a unique, random string to each password, ensuring that identical passwords
  result in different hashes.
- Peppering involves adding a secret value to the password before hashing, providing an
  additional layer of security.

### Selecting the Right Hashing Algorithm

While many hashing algorithms exist, modern security practices favor those designed to be
slow and computationally intensive, such as Argon2id, to resist brute-force attacks. The
choice of algorithm is crucial in maintaining the integrity and security of user data.

---

## Password Hashing FAQs

### What is password hashing?

**Password hashing** is a cybersecurity technique used to transform a plaintext password
into a unique, fixed-size string of characters known as a password hash.

### What is a password hash? What are hashed passwords?

A "hashed password" / "hash" is the output of password hashing, so the unique, fixed-size
string of characters that can't be computationally reversed to obtain the password.

### What makes password hashing secure?

- Password hashing secures user data by transforming passwords into cryptographic hashes,
  making it extremely difficult / impossible for unauthorized parties to reverse-engineer
  the original password.

### Can hashed passwords be cracked?

- While theoretically more secure, hashed passwords can still be vulnerable to attacks
  like brute-force or dictionary attacks. However, techniques such as salting and
  peppering significantly increase the complexity and security of hashed passwords.

### Why is salting important in password hashing?

- Salting is crucial because it ensures that even if two users have the same password,
  their hashed passwords will be different, preventing attackers from using precomputed
  hash tables to crack passwords.

### How does peppering enhance password hashing security?

- Peppering adds an extra layer of security by incorporating a secret value into the
  password before hashing. Unlike a salt, which is stored in the database, a pepper is
  kept secret, making it harder for attackers to crack the hash even if they have access
  to the database.