Crypt pad
CryptPad is an open-source, privacy-focused collaboration platform designed to provide secure and encrypted tools for document editing, file sharing, and team collaboration. Developed as an alternative to mainstream platforms like Google Docs, CryptPad prioritizes user privacy through its robust implementation of end-to-end encryption. This ensures that all data is encrypted on the user's device before being transmitted to the server, making it inaccessible to service providers, administrators, or potential attackers. Its zero-knowledge architecture means that even the platform's operators cannot access users' content, offering confidentiality.
CryptPad provides a suite of applications tailored for collaborative work. These include tools for rich text editing, spreadsheets, slideshows, Kanban boards for project management, code/Markdown editing, whiteboards for brainstorming, and polls for decision-making. Each application supports real-time collaboration, allowing multiple users to work on the same document simultaneously while maintaining data security. Unlike traditional platforms, CryptPad uses symmetric encryption with a unique key for each document. This key is embedded in the document's link, enabling seamless sharing but requiring users to manage access carefully since links effectively serve as decryption keys.
The platform's commitment to open-source principles is evident in its publicly available source code, hosted on GitHub under the AGPLv3 license. This transparency allows developers and organizations to audit the code for security vulnerabilities or customize it to meet specific needs. CryptPad can be self-hosted, giving users full control over their data and compliance with data sovereignty regulations. For those who prefer managed services, CryptPad offers a cloud-hosted version at CryptPad.fr with free and paid subscription tiers based on storage capacity and additional features.
A key strength of CryptPad lies in its privacy-centric design. User accounts are secured using cryptographic keys derived from their username and password. This approach ensures that passwords are never stored on the server and that even usernames remain invisible to administrators. Additionally, CryptPad minimizes metadata exposure by preventing operators from accessing document content or user activity logs. However, users are advised to select trustworthy server instances and follow best practices—such as using strong passwords and enabling two-factor authentication (2FA)—to maximize security.
Despite its strengths in privacy and security, CryptPad has some limitations. For example, when sharing a document link, the embedded decryption key grants irrevocable access to recipients. To revoke access, users must create a copy of the document and destroy the original. Moreover, while CryptPad is private by design, it does not guarantee anonymity; IP addresses and other metadata may still be visible to server operators unless mitigated with tools like VPNs or Tor.
CryptPad also incorporates features aimed at enhancing usability and accessibility. Recent updates have introduced Web Content Accessibility Guidelines (WCAG) compliance improvements and mobile optimizations to ensure a seamless experience across devices. The platform supports integration with services like Nextcloud for encrypted file storage and collaboration within existing ecosystems. Additionally, administrative tools allow server operators to moderate content effectively by archiving or deleting accounts that violate terms of service.
CryptPad is a collaboration suite that combines open-source flexibility with encryption to deliver a secure alternative to proprietary platforms. Its emphasis on privacy makes it particularly appealing for individuals and organizations handling sensitive information or seeking compliance with strict data protection standards. While it requires careful management of shared links and trust in server operators for certain aspects of security, CryptPad remains one of the most robust tools available for secure online collaboration.
