Bcrypt Generator

MD5 and SHA-256 are fast — billions of hashes per second on a GPU. That makes them terrible for passwords: an attacker with your hash database can brute-force millions of passwords quickly. Bcrypt is deliberately slow with a configurable cost factor. As hardware gets faster, you increase the cost factor.

The cost factor is an exponent: hashing rounds = 2^cost. Cost 10 = 1024 rounds; cost 12 = 4096 rounds. Higher cost = slower hashing = better security, but more CPU per login. The standard recommendation is cost 10–12. Choose the highest cost where login time stays under 100–300ms on your server.

Yes. A bcrypt hash ($2b$12$...) contains the algorithm version, cost factor, 22-character Base64 salt, and 31-character hash — all concatenated. You never store the salt separately. When verifying, the library extracts the salt from the stored hash and rehashes the candidate password to compare.

All three are designed to be slow. Bcrypt is the oldest (1999) and most widely supported. Argon2 won the Password Hashing Competition in 2015 and is the modern recommendation — it also has a memory-hardness parameter that makes GPU attacks more expensive. For new applications, Argon2id is preferred; bcrypt is fine for existing systems.