CryptPad is a private-by-design alternative to cloud document services like Google Docs. The CryptPad FAQ page describes the tool as a "Zero Knowledge Web Service [that] encrypts user data in the user's browser, without the server ever having access to the unencrypted data or the encryption keys." CryptPad uses Daniel J. Bernstein's Salsa20-Poly1305 cipher to encrypt data. Salsa20 was in the final "portfolio" of ciphers recommended for widespread adoption by the European Union's eSTREAM research project. CryptPad currently supports a number of common formats: rich text (i.e. word processing), computer code, presentations, polls, Kanban boards, and collaborative whiteboards. Pads created anonymously will automatically expire after three months of inactivity. Users may opt to create an account to retain documents longer. No account is necessary to edit a document, users simply exchange links. The software underlying cryptpad.fr is free software, distributed under the GNU Affero General Public License, with source code available on GitHub. Instructions for self-hosting an instance of CryptPad can be located on the GitHub README.