Think about what you write in your diary: fears, dreams, relationship issues, health concerns, financial worries, secrets you haven't told anyone. Now ask yourself: who else can read it?
The Privacy Problem with Most Diary Apps
Most journal apps store your entries in ways that allow the company — and potentially hackers, employees, or law enforcement — to read them:
- Unencrypted storage: Your entries stored as plain text on their servers
- Encryption they control: They hold the keys, so they can decrypt anytime
- AI analysis: Your entries are scanned to "provide insights" (and train AI models)
- Cloud voice processing: Your voice recordings sent to third-party servers
What "Zero-Knowledge" Means
Zero-knowledge encryption means the company literally cannot read your data, even if they wanted to:
- Your entries are encrypted on your device before syncing
- Only you have the key (derived from your password)
- The company stores encrypted data they cannot decrypt
- Even if servers are hacked, your content remains private
This is the gold standard for privacy. Very few apps actually implement it.
Why Voice Journaling Privacy Matters
Voice journaling is fast and natural, but most apps send your audio to cloud services like Google, Amazon, or OpenAI for transcription. This means:
- Your voice recordings pass through third-party servers
- They may be stored, analyzed, or used for AI training
- Your emotional state is captured in your voice
True voice privacy requires on-device transcription — processing your voice locally so it never leaves your phone.
The AI Problem
Many journal apps now offer AI features: mood analysis, emotional insights, personalized prompts. But consider the trade-off:
- AI analysis requires reading your entries
- Your thoughts become AI training data
- Patterns in your mental state are analyzed by algorithms
We believe your diary should be a private space, free from AI surveillance. That's why Hello Diary deliberately doesn't analyze your content.
What to Look for in a Private Diary App
- Zero-knowledge encryption — Company can't read your entries
- End-to-end encryption — Data encrypted in transit and at rest
- On-device voice processing — Audio never leaves your phone
- Biometric lock — Fingerprint/face access
- No AI analysis — Your thoughts aren't being scanned
- Transparent privacy policy — Clear about what they can and can't see
Why We Built Hello Diary
We created Hello Diary because we couldn't find a journal app that took privacy seriously enough:
- Zero-knowledge encryption from day one
- On-device voice transcription using open-source technology
- No AI analysis of your content
- We can't read your entries even if we're legally compelled
Your diary should be the most private space in your digital life. We built it to be exactly that.
Learn more about our approach in our zero-knowledge encryption deep dive.