bcrypt vs SHA-256: Where Do They Differ?
Both bcrypt and SHA-256 produce a fixed-size digest, but they were designed for opposite jobs. SHA-256 is an all-purpose fast hash; bcrypt is a deliberately slow password hash. This article contrasts them so you can pick the right one for storing credentials.
What Is the Core Difference Between bcrypt and SHA-256?
SHA-256 is fast and un-keyed: the same input always yields the same 256-bit digest, with no salt by default. bcrypt is slow and adaptive: it applies a scalable work factor and an embedded salt, which makes each password cost real compute time to test.
Why Is Speed a Weakness for Password Hashing?
For passwords, fast is dangerous. A GPU can try billions of candidates per second, so a plain SHA-256 of a password falls to brute force quickly. bcrypt slows each attempt on purpose, so an attacker gets far fewer guesses in the same time budget.
How Do bcrypt's Salt and Work Factor Help?
The embedded salt makes identical passwords hash differently, defeating rainbow tables. The work factor (cost) can be raised over time as hardware improves, letting you keep the hash safe without switching algorithms.
When Should You Use Each One?
Use bcrypt (or another purpose-built KDF) whenever you store passwords or derive secrets. Use SHA-256 for checksums, signatures, and general integrity where speed and a fixed length matter. Generate or compare hashes with the hash generator.