Bcrypt Hash Generator & Verifier
Generate robust Blowfish-based password hashes with adjustable work factor costs, or test and verify existing hashes directly in your browser.
1,024 key expansion rounds (2^10)
How Bcrypt Protects Passwords from Modern Attacks
1. Exponential Work Factor (2^Cost)
Unlike fast algorithms (MD5, SHA-256) designed for streaming bandwidth, Bcrypt is intentionally slow. Each increment in cost doubles the computation iterations, maintaining brute-force immunity as Moore's Law accelerates hardware.
2. Built-in 128-bit Salt
Every Bcrypt hash embeds an unpredictable 16-byte random salt. This ensures that two identical passwords yield completely distinct hash strings, neutralizing precomputed rainbow table dictionaries and multi-target cracking.
3. ASIC & GPU Resistance
Bcrypt's EksBlowfish setup heavily relies on data-dependent memory accesses across 4KB S-boxes. Parallel hardware such as graphics cards and ASIC miners encounter severe memory latency bottlenecks when attempting batch cracking.
Bcrypt Cost Factor Recommendations
| Cost Factor | Iterations | Approx. Latency | Recommended Use Case |
|---|---|---|---|
| 04 - 08 | 16 - 256 | < 15 ms | Automated unit test suites & staging mock data |
| 10 (Default) | 1,024 | ~80 - 150 ms | Production web applications & OAuth user login |
| 12 | 4,096 | ~350 - 700 ms | High-security banking, healthcare, and enterprise vaults |
| 14+ | 16,384+ | > 1,500 ms | Offline key derivation & cold-storage master keys |