CryptPad

CryptPad is a revolutionary collaboration suite developed by XWiki SAS, a French company headquartered in Paris. What sets CryptPad apart from virtually every other online office suite is its zero-knowledge architecture: all content is encrypted in your browser before it ever reaches the server. This means that even the CryptPad administrators cannot read your documents, making it one of the most privacy-respecting collaboration tools available anywhere.

French Innovation in Privacy Technology

CryptPad was created by XWiki SAS, a company with over 15 years of experience in open-source collaboration software. The project has received funding from European research programs including NGI (Next Generation Internet) and has been recognized for its innovative approach to privacy-preserving technology. Being based in France places CryptPad under the protection of both French data protection law (CNIL) and the broader GDPR framework.

The French government has shown strong support for digital sovereignty initiatives, and CryptPad aligns perfectly with these goals. Several French public institutions and organizations use CryptPad as part of their commitment to protecting citizen data and maintaining European technological independence.

Zero-Knowledge Architecture

CryptPad's zero-knowledge architecture is its defining feature. When you create a document, all content is encrypted in your browser using strong cryptographic algorithms before being sent to the server. The encryption keys are derived from a combination of your password and document-specific keys, and these keys never leave your device in unencrypted form. The server only ever sees encrypted blobs of data.

This architecture has profound privacy implications. Even if CryptPad's servers were compromised, or if law enforcement demanded access to your data, the encrypted content would be meaningless without your keys. This is fundamentally different from services like Google Docs, where your content is accessible to the service provider and potentially to third parties through legal or technical means.

Comprehensive Application Suite

CryptPad offers a surprisingly complete suite of applications, all with end-to-end encryption. The Rich Text editor provides a clean interface for creating formatted documents with images, tables, and multimedia. The Code/Markdown editor is perfect for technical documentation with syntax highlighting. The Spreadsheet application supports formulas, charts, and basic data analysis. Presentations can be created with the Slides application.

Beyond traditional office applications, CryptPad includes a Kanban board for project management, a Form builder for surveys and data collection, a Whiteboard for visual collaboration, and a Diagram tool for flowcharts and mind maps. There's even a Calendar application for scheduling. All of these applications support real-time collaboration with multiple users.

Collaboration Without Compromise

Despite the strong encryption, CryptPad provides excellent collaboration features. Multiple users can edit documents simultaneously with changes appearing in real-time. The system handles conflicts gracefully using operational transformation techniques. Comments can be added to documents, and there's a chat feature for quick communication. Access controls allow you to share documents as view-only or with full editing rights.

One innovative feature is that CryptPad supports anonymous collaboration. You can create and share documents without creating an account, and participants don't need to register to contribute. This is particularly valuable for sensitive situations where participants need to remain anonymous.

Self-Hosting for Maximum Control

CryptPad is fully open source under the AGPL license, and organizations can self-host their own instances. The Docker-based installation makes deployment straightforward, and the project provides comprehensive documentation. Self-hosting gives organizations complete control over their data and allows customization of storage limits, features, and branding.

Several organizations, universities, and even national institutions run their own CryptPad instances. This demonstrates the software's maturity and the trust placed in its architecture by security-conscious organizations.

Pricing and Accessibility

CryptPad's pricing is designed to make encrypted collaboration accessible. The free tier provides 50MB of storage, which is sufficient for many documents and light use. The premium tiers start at 5 euros per month for 5GB of storage, scaling up to higher plans for users with greater needs. There are also team plans for organizations.

Importantly, the free tier has no feature restrictions beyond storage. All applications, collaboration features, and encryption capabilities are available to free users. This makes CryptPad an excellent choice for individuals and organizations with modest storage needs who prioritize privacy.

Limitations to Consider

CryptPad has some trade-offs compared to mainstream office suites. The spreadsheet application, while functional, is less powerful than Google Sheets or Excel for complex data analysis. Import and export of Microsoft Office formats works but may not preserve all formatting. The applications are web-only; there are no native desktop or mobile apps, though the web interface works well on mobile browsers.

The zero-knowledge architecture means that if you forget your password and haven't set up recovery options, your data is truly unrecoverable. This is a feature from a security perspective but requires users to manage their credentials carefully.

Who Should Use CryptPad

CryptPad is ideal for anyone who needs to collaborate on documents while maintaining strong privacy guarantees. It's particularly well-suited for journalists working with sensitive sources, activists organizing campaigns, healthcare professionals sharing patient information, lawyers collaborating on confidential cases, and any organization handling sensitive data. The European jurisdiction and zero-knowledge architecture make it one of the most privacy-respecting collaboration tools available.