# RC4 Stream Cipher

Encrypt and decrypt text using RC4 stream cipher with a key

> Canonical page: https://elysiatools.com/en/tools/rc4-encryptor

- **Category:** Format Conversion

- **Keywords:** rc4, encrypt, decrypt, cipher, stream, key, arcfour

## Overview

The RC4 Stream Cipher tool provides a straightforward way to encrypt and decrypt text using the RC4 algorithm. By entering your source text and a secret key, you can quickly transform sensitive information into ciphertext or revert encrypted strings back to their original readable format.

## Inputs

- **Input Text** (textarea): Enter text to encrypt or decrypt...
- **Key** (text): Enter encryption key...
- **Operation** (select)

## When to use

- When you need to perform lightweight encryption for simple data obfuscation tasks.
- When you are working with legacy systems or protocols that specifically require RC4 compatibility.
- When you need to verify or decode text that was previously encrypted using the RC4 stream cipher.

## How it works

- Enter the text you wish to process into the input field.
- Provide a unique secret key to serve as the basis for the cipher.
- Select either 'Encrypt' or 'Decrypt' from the operation menu.
- Click the process button to generate your transformed text output.

## Use cases

- Obfuscating configuration strings for non-critical internal applications.
- Testing and debugging legacy software that utilizes RC4 for data handling.
- Quickly encoding short messages for educational purposes regarding stream ciphers.

## Frequently asked questions

### What is RC4?

RC4 is a stream cipher that encrypts data byte-by-byte using a variable-length key.

### Is RC4 secure for modern applications?

No, RC4 is considered cryptographically broken and is not recommended for securing sensitive modern communications.

### Do I need to use the same key for decryption?

Yes, you must use the exact same key that was used during the encryption process to successfully decrypt the text.

### Can I encrypt files with this tool?

This tool is designed specifically for text input; it does not support direct file uploads or binary file encryption.

### Is my data stored on your servers?

No, all encryption and decryption operations are performed locally in your browser for your privacy.

## Related tools

- [Text Encryptor/Decryptor](https://elysiatools.com/en/tools/text-encryptor-decryptor): Simple text encryption and decryption using various algorithms
- [XOR Encryptor](https://elysiatools.com/en/tools/xor-encryptor): Encrypt and decrypt text using XOR cipher with a key
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- [Strikethrough Text](https://elysiatools.com/en/tools/strikethrough-text): Add a strikethrough line through every character via the Unicode combining mark U+0336. Plain text — no markdown needed.
- [Text Repeater](https://elysiatools.com/en/tools/text-repeater): Repeat text N times with a chosen separator — inline, new line, or a numbered countdown. The quick tool for chat spam, dramatic build-ups, and social-media effect.
- [AES Encryption Tool](https://elysiatools.com/en/tools/aes-encryption-tool): Encrypt or decrypt text and files with AES-256-GCM and export IV-based bundles
- [Atbash Cipher](https://elysiatools.com/en/tools/atbash-cipher): Encode and decode text using Atbash substitution cipher (reverses the alphabet)
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## Samples

- [Copyright-Free MP3 Audio Samples](https://elysiatools.com/en/samples/mp3-samples): Collection of royalty-free audio samples for testing and development purposes including nature sounds, meditation music, and ambient audio
- [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion
- [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion
- [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion

## Related content

- [Classical and Modern Cipher Tools](https://elysiatools.com/en/hubs/classical-and-modern-cipher-tools): Practice safe educational and CTF cipher workflows by comparing reversible classical transformations with modern encryption and recording their security limits.