What is the Rabbit cipher?

Rabbit is a high-performance stream cipher designed by Martin Boesgaard and colleagues. It uses a 128-bit key and 64-bit IV, produces up to 2^70 bytes before the state repeats, and was a finalist in the eSTREAM cipher competition.

Is Rabbit cipher secure?

Rabbit is considered reasonably secure with no known practical attacks, but it is not as widely vetted as AES or ChaCha20. For critical applications, prefer AES-256-GCM or ChaCha20-Poly1305.

Rabbit Stream Cipher — Encrypt & Decrypt Online

How to Use rabbit-cipher

Paste or enter your input into the text field.
Configure any options (format, delimiter, encoding, or mode) using the controls above the output.
The result updates instantly — no submit button required for most operations.
Click Copy or Download to take the output to your next step.

Encrypt and decrypt text with the Rabbit stream cipher. Free to use with no sign-up — the tool operates entirely in your browser, nothing sent anywhere.

How rabbit-cipher Works

rabbit-cipher is a browser-side security utility built for speed and simplicity. Paste your input and the result appears within milliseconds. The tool handles edge cases — empty inputs, special characters, large datasets — without crashing or producing silent incorrect output. If you need a related operation, check the Related Tools section below.

Accepts large inputs — no size limits imposed by this tool
Handles edge cases: empty fields, special characters, and Unicode
Copy-to-clipboard and file download for every output
Works on Chrome, Firefox, Safari, and Edge without any extensions

Frequently Asked Questions

What does rabbit-cipher do?

rabbit-cipher encrypt and decrypt text with the rabbit stream cipher. Results appear immediately — no page reloads, no waiting for a server response.

What input does rabbit-cipher accept?

Paste text directly into the input field, or type your data. Most operations handle Unicode, special characters, and multi-line inputs without issue.

How large an input can I process?

There is no hard limit imposed by this tool. Very large inputs (multi-MB text) process within your browser's available memory. For files larger than 50 MB, a command-line tool may be faster.

Can I download the output?

Yes — every output panel includes a Copy to Clipboard button and a Download as file option. Outputs are saved as plain text or the appropriate file format for the operation.

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Rabbit Stream Cipher online

Encrypt and decrypt text with the Rabbit stream cipher — runs in your browser