ChaCha20 Decryption Tool

Decrypt ChaCha20 encrypted data using the same password and settings used for encryption.

Need to encrypt data?

Or enter encryption parameters manually:

Decryption Settings

Decrypted Output

Decrypted output will appear here

Security Note: ChaCha20 is a modern, secure algorithm.

  • ChaCha20 is a stream cipher designed by Daniel J. Bernstein.
  • It's widely used in modern applications including TLS 1.3 and WireGuard.
  • Provides excellent security with high performance.
  • This tool uses PBKDF2-SHA256 for key derivation with configurable iterations.

Note about Decryption:

  • You need the exact same password used for encryption
  • The decryption will fail if the password is incorrect or parameters don't match.
  • Make sure the input JSON is in the correct format from the ChaCha20 encryption tool.
  • All encryption parameters (nonce, salt, iterations, etc.) are automatically read from the input or can be set manually.

How to Use This Tool

You can decrypt your ChaCha20-encrypted data in three ways:

  1. Upload JSON File:
    • Click the "File" tab.
    • Upload the JSON file exported from the ChaCha20 encryption tool.
    • Enter the password used for encryption.
    • Click "Decrypt".
  2. Manual Input:
    • Click the "Text" tab.
    • Fill in all encryption parameters (ciphertext, salt, nonce, iterations, output format). The key size is fixed at 256 bits for ChaCha20.
    • Enter the password used for encryption.
    • Click "Decrypt".
  3. Paste JSON:
    • Click the "Text" tab.
    • Paste the complete JSON from the ChaCha20 encryption tool into the "Input JSON" area.
    • Enter the password used for encryption.
    • Click "Decrypt".

Important Notes for ChaCha20 Decryption:

  • The decryption will fail if the password or any parameter is incorrect.
  • ChaCha20 uses a fixed 256-bit key. This is automatically handled.
  • Ensure all parameters (salt, nonce, iterations, output format) match those used during encryption.
  • For manual input, at minimum you need: ciphertext, salt, and nonce. Other parameters will use defaults if not specified.
  • Salt must be 16 bytes (32 hex characters) and nonce must be 12 bytes (24 hex characters).

About ChaCha20 Decryption

What is ChaCha20?

ChaCha20 is a stream cipher designed by Daniel J. Bernstein. It's a modern, secure alternative to AES that provides excellent performance and security. This decryption tool allows you to recover the original data that was encrypted using ChaCha20.

Technical Specifications:

  • Type: Stream cipher
  • Key size: 256 bits
  • Nonce size: 96 bits (12 bytes)
  • Designer: Daniel J. Bernstein

Why Stream Cipher?

ChaCha20 is a stream cipher, which means it generates a keystream that is XORed with the plaintext. This provides several advantages including high performance and the ability to encrypt data of any length without padding.

Stream Cipher Advantages:

  • No padding required
  • High performance
  • Parallel processing friendly
  • Constant-time operations

Security Features

✅ Security Strengths:

  • 256-bit key provides excellent security
  • Resistant to timing attacks
  • Widely analyzed and trusted
  • Used in TLS 1.3 and WireGuard
  • No known vulnerabilities

ChaCha20 is considered one of the most secure and efficient encryption algorithms available today.

Decryption Process

ChaCha20 decryption reverses the encryption process using the same algorithm. Since it's a stream cipher, the same operation (XOR) is used for both encryption and decryption.

Required Parameters:

  • Encrypted ciphertext
  • Original password
  • Salt and nonce (initialization vector)
  • Key derivation function (PBKDF2)
  • Hash algorithm (SHA256)
  • Iteration count
  • Output format (base64/hex)

Common Issues

Wrong Password:

Decryption will fail completely or produce garbage data.

Parameter Mismatch:

Different salt, nonce, or iteration count will cause failure.

Corrupted Data:

Modified ciphertext, salt, or nonce will prevent successful decryption.

Modern Applications

ChaCha20 is widely used in modern applications and protocols, making it a reliable choice for secure communication and data protection.

Common Uses:

  • TLS 1.3 protocol
  • WireGuard VPN
  • Google's QUIC protocol
  • Secure messaging applications
  • File encryption tools