Privacy Policy

1. The Zero-Knowledge Cryptographic Model

CycleCipher operates on a strict Zero-Knowledge encryption standard:

• Client-Side Encryption: All your logs—including period start and end dates, flow intensity, physical symptoms (cramps, headaches, tender breasts), emotional states, notes, and intimacy logs—are encrypted on your Apple device using AES-256-GCM (Advanced Encryption Standard with Galois/Counter Mode authenticated encryption) prior to being written to storage.
• Secure Key Derivation: Your cryptographic master key is generated deterministically on your device using a PBKDF2 (SHA-256) key derivation function protected by Apple's hardware-backed Secure Enclave and iCloud Keychain.
• Zero Access by Developers: The developers, owners, operators, and cloud infrastructure providers of CycleCipher do not possess, store, or have access to your private decryption keys. We cannot decrypt your health data under any circumstances.

2. What Information Is Collected and Processed

A. Health and Symptom Data (Encrypted Locally)

When you log entries in CycleCipher, the following information is stored in an encrypted SQLite database on your device:

• Menstrual cycle dates, durations, and flow heaviness.
• Bodily and psychological symptoms (e.g., cramps, bloating, fatigue, mood shifts).
• User-configured cycle preferences (average cycle length, luteal phase length).

This data is processed strictly on-device by our statistical cycle prediction engine. None of this health data is transmitted to analytics servers or third-party marketing companies.

B. Account & Authentication Information

You may use CycleCipher in two distinct modes:

• Local Account Mode: No sign-in or personal account is created. All data remains strictly on your iPhone. No server interactions occur.
• Apple ID Account Mode: If you choose to enable cloud backup, you authenticate using Sign in with Apple. Apple provides an anonymous unique identifier and allows you to utilize Apple Private Relay to conceal your real email address.

C. Cloud Backup (Optional & Zero-Knowledge)

If you choose to sync your data across devices, CycleCipher transmits only an opaque, binary-encoded, authenticated AES-256-GCM ciphertext blob to our encrypted cloud store (hosted on Supabase infrastructure). The remote database stores only unreadable ciphertext and random initialization vectors (IVs). No plaintext health fields exist on the cloud database.

3. No Third-Party Tracking & No Advertisements

CycleCipher maintains an absolute zero-tolerance policy regarding tracking and surveillance capitalism:

• NO Advertising SDKs: We do not integrate Google AdMob, Meta Audience Network, or any other commercial ad SDKs.
• NO Third-Party Behavioral Trackers: We do not use Google Analytics, Firebase Analytics, AppsFlyer, or any external user-profiling telemetry libraries.
• NO Data Broker Selling: We do not sell, rent, license, or monetize personal data or health records to insurance providers, pharmaceutical companies, data brokers, employers, or government agencies.

4. In-App Purchases & Payments

All in-app purchases and lifetime unlocks are processed directly by Apple Inc. via the iOS App Store (StoreKit 2). CycleCipher does not collect, receive, or store your credit card number, bank details, billing address, or payment credentials. Financial transactions are governed exclusively by Apple's Privacy Policy and Terms.

5. Your Rights Under GDPR (European Union) & CCPA/CPRA (California)

Under international privacy laws, including the European General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA/CPRA), you have extensive rights regarding your data:

• Right to Erasure ("Right to be Forgotten"): You can permanently delete your entire account and all stored health logs at any time directly in the app via Settings → Account Management → Delete Account. This immediately purges the local database, cryptographic keys, and remote ciphertext.
• Right to Access & Portability: Since all data is stored locally in client-side storage, you retain complete physical possession of your data on your iPhone.
• Right to Restrict Processing: You may at any time choose to run CycleCipher completely offline in Local Mode without transmitting any data over the internet.

6. Apple Health & HealthKit Integration

If you choose to grant CycleCipher access to Apple HealthKit, data read from or written to HealthKit is governed by Apple's HealthKit Privacy Guidelines. CycleCipher will never use HealthKit data for marketing, advertising, or data mining purposes.

7. Children's Privacy

CycleCipher is not directed to children under the age of 13 (or under 16 in certain jurisdictions). We do not knowingly collect personal information from children.

8. Changes to this Privacy Policy

We may update this Privacy Policy from time to time. Any material changes will be reflected with an updated "Last Updated" date at the top of this page. We encourage you to review this policy periodically.

9. Contact Us

If you have any questions, concerns, or inquiries regarding our Zero-Knowledge architecture or this Privacy Policy, please contact us at:

Email: driesdrs@gmail.com