What is password hashing and why is it important?

Password hashing converts plain text passwords into fixed-length strings using cryptographic algorithms. It's essential for secure password storage because hashes are irreversible and protect user passwords even if databases are compromised.

Which hash algorithm should I use for passwords?

For password storage, use bcrypt, Argon2, or PBKDF2 as they include salt and are designed to be slow. Avoid MD5 and SHA-1 for passwords. SHA-256 can be used but requires manual salting and is too fast without key stretching.

What is the difference between MD5 and SHA-256 hashing?

MD5 produces 128-bit hashes and is cryptographically broken, while SHA-256 produces 256-bit hashes and is still secure. SHA-256 is slower and more secure, but both are too fast for password storage without additional measures.

Can password hashes be reversed?

No, cryptographic hashes are one-way functions and cannot be mathematically reversed. However, weak passwords can be cracked using dictionary attacks, rainbow tables, or brute force methods.

Password Hash Generator

Generate password hashes using various cryptographic algorithms. Perfect for developers implementing secure authentication systems.

Generate Password Hash

Create cryptographic hashes of passwords using various algorithms

Generate all common hash types

Hash Algorithm

Include salt (recommended)

Key Features

Multiple hash algorithms supported

Automatic salt generation option

Bcrypt-like format with configurable rounds

Security level indicators

Batch generation of all common hashes

Developer-friendly output format

Algorithm Security

MD5: Cryptographically broken, avoid completely

SHA-1: Deprecated due to collision attacks

SHA-256/512: Secure but need salt + key stretching

Bcrypt: Designed for passwords, use in production

Password Hashing Best Practices

Use Proper Libraries: bcrypt, Argon2, or PBKDF2

Always Salt: Prevent rainbow table attacks

Adjust Cost: Balance security vs performance

Never Store Plain Text: Always hash passwords

Frequently Asked Questions

Why should I not use MD5 for passwords?

MD5 is cryptographically broken with known collision attacks. It is also extremely fast, making brute force attacks feasible. Modern systems should never use MD5 for password storage.

What is salt and why is it important?

Salt is random data added to passwords before hashing. It prevents rainbow table attacks and ensures identical passwords have different hashes. Always use unique salts per password.

How do I implement secure password hashing in code?

Use established libraries like bcrypt (Node.js), password_hash() (PHP), or Argon2. These handle salting, cost factors, and timing attacks automatically.

What are bcrypt rounds and how many should I use?

Rounds determine computational cost - each increment doubles the time. Use 10-12 rounds for most applications. Test on your hardware to ensure reasonable response times.

Is this tool output safe for production use?

No! This tool is for education/demo only. MD5 is simulated, bcrypt is simplified. Always use proper cryptographic libraries in production applications.

What is the difference between SHA-256 and bcrypt?

SHA-256 is fast and secure but needs manual salting. Bcrypt is designed for passwords, includes built-in salting, and is intentionally slow to resist brute force attacks.

How do I verify passwords after hashing?

For bcrypt, use the library verify function. For SHA variants, hash the input password with the same salt and compare. Never store plain text passwords for comparison.

Can I use this tool to crack password hashes?

No. Cryptographic hashes are one-way functions and cannot be reversed. This tool only generates hashes from passwords, not the other way around.

What happens if two users have the same password?

Without salt, identical passwords produce identical hashes, creating security risks. With unique salts per user, identical passwords generate completely different hashes.

How do timing attacks work against password hashing?

Attackers measure hash computation time to guess password characteristics. Proper libraries like bcrypt use constant-time operations to prevent these attacks.

Why is SHA-256 not recommended for direct password storage?

SHA-256 is extremely fast, allowing billions of hash attempts per second. Password-specific algorithms like bcrypt are intentionally slow to make brute force attacks impractical.

What is the difference between hashing and encryption?

Hashing is one-way and irreversible, perfect for password storage. Encryption is two-way and reversible with a key, used for data that needs to be decrypted later.