root@generate-random:~/salts$ _

Cryptographic Salt Generator

Generate cryptographically secure random salts for password hashing and authentication systems

[ Cryptographic Salts - Quick Summary ]

What: Generate cryptographically secure random salts for password hashing and key derivation. Uses PHP random_bytes (CSPRNG) for production-ready security. Supports Base64, Base64URL, Hex, and Alphanumeric encoding with configurable length (8-128 characters). Salts are random data added to passwords before hashing to ensure identical passwords produce different hashes.

When to use: Password hashing with bcrypt/Argon2/PBKDF2/scrypt when not auto-generated, key derivation functions, custom cryptographic protocols, session token creation, database encryption key derivation. Protects against rainbow table attacks by making each hash unique. Essential for older hash functions (SHA-256, MD5) that don't auto-generate salts.

Example: Base64: yH3kT9mN5pQ2xR7jL4wV6sZ8aB1cD0eF. Hex: a3f7c9e2b5d8f1a4c6e9b2d5f8a1c4e6. Usage: hash(password + salt)

Security/Important: FOR TESTING ONLY. Each password MUST have a unique salt - never reuse salts across passwords. Use 16-32 characters for password hashing (longer provides marginal additional security). Salts can be stored in plain text alongside password hashes - they are not secrets. Modern password hashing (bcrypt, Argon2, scrypt) auto-generates and includes salts - separate salt generation only needed for older hash functions or custom protocols. Generated with CSPRNG suitable for production. Store salt with hash for verification.

Our cryptographic salt generator helps you generate secure random salts for password hashing and authentication systems. Generate-Random.org provides a free salt generator that creates cryptographically secure salts using PHP's random_bytes() function. This secure salt tool supports multiple encoding formats including Base64, Base64URL, Hexadecimal, and Alphanumeric. Generate up to 25 salts at once with configurable length (8-128 characters) for bcrypt password hashing, key derivation functions, and cryptographic applications. All salts generated using CSPRNG for production-ready security. No signup required, completely free.

What is a Cryptographic Salt Generator?

A Cryptographic Salt Generator creates random data strings that are added to passwords before hashing to protect against rainbow table attacks and ensure identical passwords produce different hashes. Our generator uses PHP's random_bytes() function to create cryptographically secure salts suitable for production use in authentication systems.

Salts are essential in password security, making it impossible for attackers to use pre-computed hash tables (rainbow tables) to crack passwords. Each password should have a unique salt, which is stored in plain text alongside the password hash. Modern password hashing functions like bcrypt and Argon2 automatically generate and include salts, but separate salts are needed for custom cryptographic protocols and older hash functions.

Salt Generator Configuration Options

Length (8-128 Characters)

Configurable salt length from 8 to 128 characters. For password hashing, 16-32 characters is typically sufficient. Longer salts (64-128) provide additional security margin but with diminishing returns. The length determines how many unique possible salts can be generated—longer salts make collisions exponentially less likely. Choose based on your security requirements and storage constraints.

Encoding Format

Base64 (Default): Standard Base64 encoding (A-Z, a-z, 0-9, +, /). Most common format for salts. Base64URL: URL-safe Base64 (A-Z, a-z, 0-9, -, _). Safe for URLs and filenames without escaping. Hexadecimal: Hex encoding (0-9, a-f). Widely compatible and human-readable format. Alphanumeric: Letters and numbers only (A-Z, a-z, 0-9). Maximum compatibility, no special characters.

Count (1-25 Salts)

Generate between 1 and 25 unique salts in a single batch. Each salt is generated independently using cryptographically secure random bytes, ensuring all salts are unique and unpredictable. Useful for batch password hashing operations, pre-generating salts for a user registration system, or testing.

Include Length Information

Enable to include the actual character length of each generated salt in the output. Useful for verification and debugging, especially when working with different encoding formats where byte length differs from character length. Provides transparency about what was generated.

How to Generate Cryptographic Salts

[STEP 1] Choose Encoding

Select encoding format: Base64 for standard use, Base64URL for URLs, Hex for compatibility, or Alphanumeric for maximum compatibility.

[STEP 1] Set Length

Configure salt length (8-128 characters). Use 16-32 characters for password hashing, longer for extra security.

[STEP 1] Configure Quantity

Set how many salts to generate (1-25). Each salt is cryptographically unique and independent.

[STEP 1] Generate & Export

Click generate and export results in TXT, CSV, or JSON format with encoding metadata included.

Common Use Cases for Cryptographic Salts

_ Password Hashing: Generate unique salts for each password in authentication systems to prevent rainbow table attacks
_ Key Derivation: Use salts with PBKDF2, scrypt, or Argon2 to derive encryption keys from passwords
_ Custom Protocols: Create salts for custom cryptographic protocols that don't auto-generate them
_ Session Security: Generate salts for session token creation and CSRF token generation
_ Database Encryption: Use salts for deriving database encryption keys from master passwords
_ Testing & Development: Create test salts for cryptographic function testing and security audits

Technical Details: Salt Generation

Our salt generator uses PHP's random_bytes() function to generate cryptographically secure random data from the operating system's CSPRNG (Cryptographically Secure Pseudo-Random Number Generator). The random bytes are then encoded in the selected format (Base64, Hex, etc.) to the specified length.

// Salt Generation Process
Input: length, encoding, count

For each salt i from 1 to count:
  1. Calculate bytes needed based on encoding:
     - Hex:         length / 2 bytes
     - Base64:      length * 3 / 4 bytes
     - Base64URL:   length * 3 / 4 bytes
     - Alphanumeric: length bytes (CSPRNG loop)

  2. Generate cryptographically secure random bytes:
     random_bytes = random_bytes(bytes_needed)

  3. Encode based on format:
     - Hex:         bin2hex(random_bytes)
     - Base64:      base64_encode(random_bytes)
     - Base64URL:   strtr(base64_encode(), '+/', '-_')
     - Alphanumeric: random_int() loop with charset

  4. Truncate to exact length
  5. Return salt with optional metadata

Properties:
- Cryptographically secure: Uses OS CSPRNG
- Unique: Each salt is independently generated
- Unpredictable: No patterns or sequences
- Any length: Configurable from 8 to 128 characters
- Multiple formats: Base64, Base64URL, Hex, Alphanumeric

Security Notes:
- Safe for production password hashing
- Each password should have unique salt
- Salts can be stored in plain text
- Modern hash functions (bcrypt, Argon2) auto-generate salts

API Access for Developers

GET https://generate-random.org/api/v1/generate/salts

VIEW FULL API DOCUMENTATION →

Frequently Asked Questions

What is a cryptographic salt? ▶

A cryptographic salt is random data added to a password before hashing. It ensures that identical passwords produce different hashes, protecting against rainbow table attacks and making password databases more secure. Each password should have a unique salt stored alongside its hash.

How long should a salt be? ▶

For password hashing, a salt of 16-32 characters is typically sufficient. Longer salts (64-128 characters) provide additional security margin, though the benefit is marginal beyond 32 characters. Our generator supports salts from 8 to 128 characters to accommodate different security requirements.

Which encoding format should I use? ▶

Base64 is the most common choice for salts and works well in most scenarios. Use Base64URL if you need URL-safe encoding (no + or / characters), Hexadecimal for maximum compatibility and readability, or Alphanumeric if you need to completely avoid special characters.

Can I reuse the same salt for multiple passwords? ▶

No. Each password should have a unique salt. Reusing salts defeats their purpose and makes your password database vulnerable to attacks. If two passwords use the same salt and happen to be identical, their hashes will also be identical, revealing that information to attackers.

Is it safe to store salts in plain text? ▶

Yes. Salts are not secrets and can (and should) be stored in plain text alongside password hashes. Their purpose is to make each hash unique and prevent rainbow table attacks, not to keep the hashing process secret. Modern password hashing functions like bcrypt and Argon2 include the salt directly in the hash output.

Are these salts cryptographically secure? ▶

Yes. All salts are generated using PHP's random_bytes() function, which uses the operating system's cryptographically secure pseudo-random number generator (CSPRNG). This makes them suitable for production use in password hashing, authentication systems, and cryptographic applications.

Do I need a salt if I'm using bcrypt or Argon2? ▶

No. Modern password hashing functions like bcrypt, Argon2, and scrypt automatically generate and include a unique salt as part of the hash. You only need to generate separate salts when using older hash functions like SHA-256 or MD5, or when implementing custom cryptographic protocols.

[ HOW TO CITE THIS PAGE ]

APA Style:
Generate-Random.org. (2025). Cryptographic Salt Generator. Retrieved from https://generate-random.org/salts

Web Citation:
Cryptographic Salt Generator - Generate-Random.org (https://generate-random.org/salts)