Password hashing

Definition

Password hashing is a cryptographic process that transforms a plaintext password into a fixed-length string of characters, which appears random and is designed to securely store passwords. This process is essential for protecting user credentials from unauthorized access, ensuring that even if a database is compromised, the actual passwords remain hidden and difficult to retrieve. Hashing algorithms are specifically designed to be one-way functions, making it nearly impossible to reverse the process and recover the original password.

5 Must Know Facts For Your Next Test

1. Password hashing uses algorithms like bcrypt, Argon2, or PBKDF2, which are specifically designed to be slow and resource-intensive to thwart brute force attacks.
2. Each time a password is hashed, it should be combined with a unique salt value to ensure that even identical passwords produce different hashes.
3. Good password hashing practices require using algorithms that resist attacks, such as rainbow table attacks, by incorporating computational complexity.
4. When users change their passwords, the new password must be rehashed and stored, while the old hash remains until replaced or deleted.
5. It is important to periodically review and update the hashing methods used as computational power increases over time, making older algorithms potentially vulnerable.

Review Questions

• How does the use of salt enhance the security of password hashing?
  • The use of salt in password hashing adds a random value to each password before it is hashed. This means that even if two users have the same password, their hashes will be different due to the unique salt values. This significantly enhances security by preventing attackers from using precomputed tables, known as rainbow tables, to quickly crack multiple passwords at once.
• Discuss the importance of selecting strong hashing algorithms in securing stored passwords and protecting against cyber threats.
  • Choosing strong hashing algorithms is crucial for securing stored passwords because weak algorithms can be easily broken through techniques such as brute force or pre-computation attacks. Modern algorithms like bcrypt and Argon2 are designed to be slow and resistant to such attacks, making it much harder for attackers to gain access to user credentials. Additionally, these algorithms can adapt over time as computing power increases, ensuring continued protection against evolving threats.
• Evaluate the implications of compromised databases on hashed passwords and how proper hashing practices can mitigate these risks.
  • If a database containing hashed passwords is compromised, proper hashing practices significantly reduce the risk of exposing actual passwords. Since hashed passwords cannot be easily reversed due to their one-way nature, attackers face substantial challenges in recovering original passwords. By using techniques such as salting and selecting robust hashing algorithms, organizations can further enhance security measures that safeguard user credentials even in cases of data breaches. Moreover, adopting strategies like frequent updates to hashing methods allows organizations to stay ahead of potential vulnerabilities associated with outdated algorithms.

Related terms

Salt: A random value added to a password before hashing to ensure that identical passwords yield different hash values, providing additional security against attacks.

Hash Function: An algorithm that takes an input (or 'message') and returns a fixed-size string of bytes, typically a digest that is unique to each unique input.

Brute Force Attack: A method used by attackers to guess passwords by systematically trying every possible combination until the correct one is found.