Privacy & Security Guide

Your Privacy Matters

At Eristotle, we believe that your journal is a sacred space. For reflection to be truly honest, you must feel completely safe. That's why we've built Eristotle with a privacy-first architecture. Unlike traditional journaling apps that sync everything to their own servers, Eristotle is built to work locally on your device using Apple's most advanced security frameworks.

Eristotle uses AES-256-GCM encryption—the industry standard for secure data transmission and storage. This isn't just software encryption; it is hardware-accelerated and deeply integrated with your device's hardware.

How it works:

• CryptoKit: We use Apple's native CryptoKit framework to perform cryptographic operations, ensuring high performance and resistance to side-channel attacks.
• The Keychain: Your unique encryption master key is stored in the iOS Keychain, protected by the Secure Enclave. This key never leaves the secure hardware of your device.
• Per-Entry Encryption: Every journal entry, transcription, and therapeutic insight is encrypted individually before being saved to the database.

By default, Eristotle is a local-first app. This means your data stays where it belongs: on your iPhone or iPad.

Eristotle offers an encrypted backup feature that lets you create offline copies of your journal, protected by a 12-word recovery phrase. This ensures you can recover your data even if you lose access to your iCloud account.

• 12-Word Recovery Phrase: Uses BIP39, the same secure standard used by cryptocurrency wallets, to create an easy-to-remember but cryptographically strong key for your backups.
• AES-256-GCM Encryption: Your backup file is encrypted with military-grade encryption, making it safe to store anywhere — even in public cloud storage.
• Recovery Kit PDF: Export a printable Recovery Kit with your phrase and a QR code. Store it in a safe place for disaster recovery.
• iCloud-Independent: Your encrypted backup is completely separate from iCloud. Even if your Apple ID is compromised, your backup remains secure.

Eristotle gives you control over how iOS protects your files at the system level. You can adjust this in Settings → Privacy & Security.

We build on the foundation of the world's most advanced mobile security platform. Eristotle utilizes these core Apple security technologies:

• Secure Enclave: A hardware-based key manager that's isolated from the main processor to provide an extra layer of security.
• Apple Silicon: Custom Apple chips provide the cryptographic engines required for line-speed AES encryption of your data.
• Biometric Authentication: Integration with Face ID and Touch ID ensures that only you can unlock your journal.
• The iOS Sandbox: Eristotle runs in a strictly isolated environment (the "sandbox"), which prevents other apps from accessing your private files or encryption keys.