DEV Community: arkwarden

3 iPhone Privacy Settings People Mix Up, and the Test They All Fail

arkwarden — Sun, 27 Sep 2026 08:54:18 +0000

"How do I lock my photos on iPhone?" sounds like one question. It is really three, and iOS answers each one with a different setting:

Hide some photos so they do not show up when someone scrolls.
Lock the Photos app so it asks for Face ID before it opens.
Put a password on one folder of files.

People mix these up all the time, and the settings do not make it easy. Here is what each one does, where to find it on iOS 27 and earlier, and what it keeps private.

1. The Hidden album: out of sight

Hiding a photo moves it out of your Library, your other albums, and the Photos widget. It goes into one album called Hidden.

To find it: open Photos, tap Collections, scroll to Utilities, and tap Hidden. Then tap View Album and use Face ID, Touch ID or your passcode.

If Hidden is missing, someone turned the album off in Settings. The photos are still on your phone. Where the switch lives depends on your iOS version:

iOS 27: Settings → Apps → Photos → Albums → Hidden Album
iOS 18 to iOS 26: Settings → Apps → Photos → Show Hidden Album

Right above that switch is the lock: Use Face ID, Use Touch ID or Use Passcode, depending on how your iPhone unlocks. Keep it on.

What it keeps private: a stranger scrolling through your phone will not see those photos, and cannot open the album without your face or fingerprint. But when Face ID or Touch ID fails, the album offers your passcode instead. So anyone who knows your passcode can open it.

There is a full walkthrough with screenshots for iOS 27 and iOS 26 in this guide on how to find hidden photos on iPhone.

2. Locking the Photos app: an extra check at the door

Since iOS 18, you can lock almost any app, including Photos.

To turn it on: touch and hold the Photos icon on your Home Screen, tap Require Face ID (or Require Touch ID or Require Passcode), then tap it again on the next screen to confirm.

From then on, Photos asks for Face ID, Touch ID or your passcode every time it opens. When you close the app, it locks again.

What it keeps private: the whole app, not just some photos. A friend you hand your phone to cannot open Photos without passing that check. The lock stays on this iPhone only. It does not follow you to your iPad or Mac.

Two details that surprise people: Apple does not let you hide built-in apps like Photos, only lock them. And like the Hidden album, the lock opens with your passcode too.

More detail, including how the app lock and the Hidden album work together, is in this guide on how to lock photos on iPhone.

3. A password on one folder: not built in

The honest answer surprises most people: the Files app cannot put a password on a single folder.

What you can do instead:

Lock the whole Files app, the same way as Photos: touch and hold its icon and tap Require Face ID.
Lock a note in the Notes app. Notes can use your iPhone passcode or a separate Notes password.
Use a vault app that encrypts the files and supports folders.

Home Screen folders, the ones that group your apps, cannot be locked at all.

This guide explains each option and when it makes sense: how to lock a folder on iPhone.

The one thing all three have in common

Put the three side by side and a pattern shows up:

Setting	Hides from a scroll	Asks before opening	Opens with your passcode
Hidden album	Yes	Yes, when the lock is on	Yes
Photos app lock	No	Yes	Yes
Files app lock	No	Yes	Yes

Every built-in option ends in the same place: your iPhone's own Face ID, Touch ID or passcode. For a stranger, that is plenty. For someone who knows your passcode, such as a partner, a child, or anyone who has watched you type it, none of these settings is a separate lock.

That is a design choice, not a bug. Apple built these features to keep things out of sight and add a quick check. They were never meant to give some files a key of their own.

Now try the same test with ArkWarden

Hand your unlocked iPhone to someone who knows your passcode. The Hidden album opens. Photos opens. Files opens.

ArkWarden does not.

Your passcode does not open it. The vault opens with a pattern you draw on a 5×5 grid. Every file is encrypted on your iPhone with AES-256-GCM.
Copying the files does not help. Part of the key lives in your iPhone's Secure Enclave, so copied vault files cannot be attacked on another computer.
If someone insists you open it, open Wing. Wing is a second, fully working vault with its own pattern and its own files.
You can see who tried. Turn on Intruder Detection, and ArkWarden takes an encrypted front-camera photo after 3, 5 or 10 wrong patterns.
You can add a physical key. Tap a YubiKey after your pattern. ArkWarden passed Yubico's technical review for the Works with YubiKey catalog.
There is no account and no server. Nobody else holds a copy of your files or your key, and folders work inside the vault just like in Files.

The built-in settings keep your photos out of sight. ArkWarden keeps them private, even from people who know your passcode.

Get ArkWarden on the App Store

A Photo Vault Is Not a Lock Screen

arkwarden — Thu, 13 Aug 2026 19:16:22 +0000

A private-file app can look convincing before it has explained the one thing that matters most: what happens to a file after import.

A passcode, pattern, or biometric prompt can control whether someone can open an app. That is useful. It does not, on its own, explain whether the photo, video, recording, or document stored by the app is unreadable without a cryptographic key.

For an iPhone privacy app, those are separate questions. A screen lock is an interface decision. Encryption is a storage decision.

At ArkWarden, that distinction is the starting point for the product. We build a private vault for photos, videos, audio, and documents, but the more general point applies to any app that asks users to trust it with sensitive material.

The stored file needs its own protection

An app can require Face ID or a PIN and still leave the stored file in its original form. If another process can reach that file through an export, backup, device connection, or an implementation mistake, the app-level prompt was never the protection boundary.

The useful question is concrete: does the app turn the stored file into ciphertext that cannot be opened without the correct key?

ArkWarden encrypts each file on the device with AES-256-GCM through Apple CryptoKit. Authentication matters as much as confidentiality here. A system should reject changed or substituted encrypted data rather than quietly opening it as though it were valid.

Naming an algorithm is not enough by itself. An honest description should explain where the key comes from, what unlock secret protects it, and what recovery path exists when the user forgets that secret.

Key custody is a product decision

Many privacy products make an account part of the access or recovery path. That can be useful when someone needs password reset, multi-device synchronization, or customer support. It also means the provider and an email address have a role in access to private material.

ArkWarden takes a local-first approach. Normal use does not require an ArkWarden account or an ArkWarden server. ArkWarden creates a random 256-bit master key on the iPhone and never sends it elsewhere. For pattern unlock, the pattern goes through PBKDF2 at 600,000 iterations with a vault-specific salt. ArkWarden combines that result with a secret from the iPhone's Secure Enclave. Both are required to unlock the master key, so copied vault data cannot be attacked on another computer. Users can choose Face ID or Touch ID, a PIN, or YubiKey NFC as a second factor.

This approach has a cost: there is no email reset. Instead, a user can create a 12- or 24-word recovery phrase and keep it somewhere safe. That is not universally better. It is a deliberate trade: more user control, and more user responsibility.

A recovery path should not create a new weak point

Privacy apps need a clear answer for two different failures:

The user forgets how to unlock the vault.
The device, backup, or file list needs recovery.

Those are not the same problem. A password-reset email addresses the first one, but it also places the provider in the access path. A recovery phrase held by the user avoids that provider reset path, but it must be treated like a key because it is one.

For data recovery, an app should explain what its backup contains, whether it remains encrypted, and what is required to restore it. ArkWarden supports encrypted backup through a user's own iCloud account or an exported encrypted backup file. Both are optional. Restoring requires the recovery phrase.

Transparency should be practical

Security claims are easier to make than to check. The useful standard is not that every user must read cryptographic code. It is that a technically experienced person has something real to inspect, and that the product does not ask everyone else to rely on unexplained promises.

ArkWarden publishes its core encryption source code. That does not make an app automatically secure, and it is not a substitute for independent review. It does make the relevant design choices available for inspection instead of treating them as marketing language.

For an example of how these questions apply to actual products, ArkWarden has published a source-led comparison of seven photo vault apps for iPhone. It links to each provider's public documentation and marks technical details as undocumented rather than guessing.