Privacy, structurally
Privacy pages usually ask you to trust a policy. This one describes an architecture. OpponentBook makes two distinct promises — one that is always true by construction, and one you can opt into.
Claim A — always true, any mode
Your journal — opponent observations, match reflections, training entries, photos, video — is written to storage you already own: Google Drive, Dropbox or iCloud. It is never stored on servers we control. We cannot read your notes for the same reason your neighbour cannot — we don't have them.
Claim B — optional, end-to-end encryption
In standard mode, your files sit on your cloud drive the way any file does — readable by the provider, protected by the provider's security. Turn on end-to-end encryption and your notes are sealed with AES-256-GCM on your device before upload. Google, Dropbox or Apple then store ciphertext they cannot open. The key is derived from a password only you know.
The honest trade-off — if you forget your encryption password, nobody can recover your notes. Not us, not your provider. That is what zero-knowledge means.
| What | Where it lives | OpponentBook |
|---|---|---|
| Opponent observations & match reflections | Your storage | Cannot see |
| Training entries | Your storage | Cannot see |
| Photos, video | Your storage | Cannot see |
| AI summaries & briefs you generate | Your storage | Cannot see |
| Review-tracking events | Your storage | Cannot see |
| Email & login method | Our auth provider | Sees |
| Subscription tier & billing state | Stripe / app store + our database | Sees |
| Anonymous IDs, dates and sport tags (so lists load fast) | Our database | Sees |
AI runs only when you press an AI button — generate a summary, build a brief, start dictation. Your relevant notes are sent over TLS to our AI function, forwarded to the model, and the answer is returned to you and saved to your storage. Nothing is persisted on our side; logs carry counts and latencies, never content. If you never tap an AI button, no AI call ever leaves your device.
The feature that correlates preparation with results stores its events — profile opened, note read, brief generated — as timestamps on your own storage, next to your notes. They never reach our servers. One switch stops new capture; one button erases the history.
Honesty cuts both ways. In standard mode your storage provider can technically read your files, like any file on your drive — enable E2EE if that matters to you. File names, sizes and timestamps are visible to your provider even with E2EE — and E2EE currently seals your notes and entries, not photos or video, which are stored as-is for now. And anyone holding your unlocked phone can read your journal, which is why your device's lock screen matters.
The only measurement on this site is a cookieless analytics counter that stores no personal data — no tracking pixels, no advertising cookies, no cross-site profiling. We would find it strange to promise you privacy through a page that spies on you.
