RC4 Stream Cipher Generator & Decrypter

Generate RC4 keystream sequences and encrypt or decrypt arbitrary data online with interactive Key Scheduling (KSA) and PRGA state array inspections.

How to Use RC4 Stream Cipher Generator & Decrypter

  1. Enter Stream Plaintext or Hex: Input the data to encrypt or decrypt with the RC4 stream cipher.
  2. Set Secret Key (1–256 Bytes): Provide an encryption passphrase of any arbitrary length.
  3. Generate Keystream & Bitwise XOR: Observe the Key Scheduling Algorithm (KSA) permutation and PRGA keystream output.

Frequently Asked Questions

How does RC4 generate its pseudorandom keystream?

RC4 initializes a 256-byte state array with the key (KSA), then continuously swaps array elements using two index pointers (PRGA) to output one byte per cycle.