Is bcrypt a hashing algorithm

Question

I’ve been learning about various cryptographic techniques, and I keep encountering the term bcrypt, often in relation to password storage. However, I’m not entirely clear on whether bcrypt is considered a hashing algorithm or if it’s something else. Can someone clarify this for me? How does it differ from other hashing algorithms like SHA-256?

Answer 1

Yes, bcrypt is a cryptographic hashing algorithm specifically designed for securely hashing passwords. Unlike general-purpose hashing algorithms like SHA-256, bcrypt incorporates a salt and is computationally intensive, making it more resistant to brute-force attacks.

Key Features of bcrypt

• Salted Hashing: Bcrypt automatically generates a unique 16-byte salt for each password, which is combined with the password before hashing. This ensures that identical passwords result in different hashes, protecting against rainbow table attacks.

• Adaptive Cost Factor: Bcrypt includes a configurable cost parameter that determines the number of iterations used in the hashing process. As computational power increases, this cost factor can be adjusted to increase the time required to compute the hash, enhancing security over time.

• Password Length Handling: Bcrypt processes passwords up to 72 bytes in length. Passwords longer than this are truncated, which is a consideration when implementing password policies.

Comparison with SHA-256

• Purpose: SHA-256 is a general-purpose cryptographic hash function designed for speed and efficiency, commonly used for data integrity verification. In contrast, bcrypt is specifically designed for securely hashing passwords, emphasizing security over speed.

• Resistance to Attacks: While SHA-256 is secure for its intended purposes, its speed makes it less suitable for password hashing, as attackers can attempt a large number of guesses in a short time. Bcrypt's computational intensity and salting mechanism make it more resistant to brute-force and rainbow table attacks.

• Adaptability: Bcrypt's adjustable cost factor allows it to remain secure as hardware capabilities evolve, whereas SHA-256 lacks this adaptability.