Why We're Building an Encrypted Alternative to Google Calendar

Open your calendar right now. Look at the last month. Doctor appointments. Job interviews. Therapy sessions. Date nights. Meetings with your lawyer. Every recurring commitment. Every cancelled plan. Your calendar doesn't just track your schedule. It tells the complete story of your life.

Now look at your contacts. Your family. Your therapist. Your ex. Your doctor. The relationships between them. Phone numbers, birthdays, home addresses. It's a map of every person who matters to you.

This data is deeply personal. And for most people, every bit of it sits on servers owned by Google, Apple, or Microsoft. Fully readable, fully analysable, and fully available to anyone with the right court order, the right exploit, or the right employee badge.

The problem nobody talks about

We have encrypted messaging now. Signal proved you could have a great user experience and end-to-end encryption. WhatsApp adopted the same protocol for billions. Proton built encrypted email. Bitwarden and 1Password encrypt your passwords.

But calendars? Contacts? Tasks? The data that structures your entire life is still sitting unencrypted on someone else's server.

Google Calendar uses TLS in transit and encrypts data “at rest”, which means Google holds the keys. They can read every event. Their systems process your calendar to show you smart suggestions, travel times, and reminders. That processing requires access to unencrypted data. Apple is better: iCloud offers Advanced Data Protection for some categories. But calendar and contacts are explicitly excluded from E2E encryption even with ADP enabled.

This isn't a theoretical risk. In 2024, a breach at a major calendar SaaS provider exposed scheduling data for thousands of organisations. Government surveillance programs have routinely targeted calendar and contact metadata. And data brokers don't even need a breach. They can infer relationships and patterns from metadata alone.

Why we started SilentSuite

SilentSuite exists because we believe your schedule and relationships deserve the same level of protection as your messages. The technology for this has existed for years. The Etebase protocol, created by the EteSync project, solved the hard cryptographic problems: zero-knowledge sync, end-to-end encrypted collections, conflict resolution, and offline-first architecture.

But EteSync became inactive. Development stopped. The apps weren't updated. The server codebase stagnated. The protocol was sound, but the product was abandoned.

So we decided to pick it up. Take the proven Etebase protocol and build a modern, maintained product around it. Not a weekend project or a hobby. A real service, with a real business model, that people can actually depend on.

What SilentSuite is

SilentSuite is encrypted sync for the rest of your digital life:

• Calendar: your events, encrypted before they leave your device
• Contacts: your relationships, visible only to you
• Tasks: your to-dos, your plans, nobody else's business

Here's what we care about:

1. Encryption is not a feature. It's the architecture.

Every piece of data is encrypted on your device before it ever touches our server. We don't offer a toggle to “enable encryption” because there's nothing to toggle. The server only ever sees ciphertext. We couldn't read your data even if we wanted to. Or were compelled to.

2. Open source by default

Our apps and server are open source. You can read the code, audit the encryption, and verify our claims. Privacy promises without transparency are just marketing. We back ours with code.

3. No lock-in, ever

Your data is yours. Export it anytime. Self-host the server if you want. We use the standard Etebase protocol, not a proprietary format designed to keep you trapped. The way to keep customers is to build a great product, not to make leaving impossible.

4. Your Data, Your Control

With end-to-end encryption and zero-knowledge architecture, your data is protected regardless of where the server is located. We comply with GDPR and privacy best practices, and because the server is open source, you can self-host for complete data sovereignty. No third party — including us — can access your unencrypted data.

5. Sustainable business, not a hobby project

Too many privacy tools are side projects that disappear when the maintainer gets busy. SilentSuite has a real business model: a paid hosted service, priced fairly, that funds continued development. We charge enough to sustain the project, and we don't supplement revenue by monetising your data. We can't. It's encrypted.

Who this is for

SilentSuite is for people who care about privacy but don't want to run their own server. The “privacy middle class”: people who use Signal, who chose Proton Mail, who switched to Bitwarden, but who still sync their calendar through Google because there wasn't a good alternative.

You shouldn't need a homelab and a computer science degree to keep your calendar private. It should be as easy as signing up and installing an app.

What happens next

We're in the early stages. The Etebase server is deployed and working. Real end-to-end encrypted sync has been tested successfully between devices. We're now building the client applications and preparing for a public beta.

Our roadmap, roughly:

1. Now: Server live, apps available, core protocol verified
2. Soon: Beta client apps (starting with Android and web)
3. Later: iOS app, CalDAV bridge for existing calendar apps, family plans
4. Future: B2B offering for organisations that need compliant, encrypted PIM

We're building this in public. We'll share progress, decisions, and the occasional hard lesson on this blog.

If this sounds like something you've been waiting for, get started today. No spam. No data harvesting.

Your calendar is your life. It should be yours alone.