Short answer: start with a strong iPhone passcode and current software, then choose storage based on your situation. Apple’s built-in data protection helps secure files on the device; an encrypted cloud service can make files available on other devices; a local vault can keep its own copy off a provider’s servers. None of these choices is complete without a recovery plan. A screen lock, hidden folder, or app password is not by itself proof that the stored files are encrypted.
Four different protections people often call “a vault”
Before comparing apps, separate the security features. They reduce different risks, and a product may offer one without offering all of them.
- Device encryption is built into iOS. Apple documents a file-level Data Protection system for iPhone, with protection tied to the device’s security hardware and passcode.
- End-to-end encryption means a service encrypts content on your device so the provider does not hold the keys needed to read it. It can protect cloud copies, but your signed-in devices and account recovery still matter.
- An app lock asks for Face ID, Touch ID, or a passcode before showing an app. That can deter casual access, but it does not tell you how the app encrypts files on disk or in backups.
- Hidden or decoy access changes what someone sees in an app. It is a separate privacy feature, not a replacement for strong encryption, a secure device, or a backup.
For important documents, ask two questions separately: “Could someone read this copy?” and “Can I recover it if my phone or account is lost?” A good answer to the first does not guarantee a good answer to the second.
Why the lost-phone scenario matters now
One current concern is a phone being stolen after someone has seen or learned its passcode. Apple’s Stolen Device Protection guidance, updated October 22, 2026, says certain sensitive actions require Face ID or Touch ID with no passcode fallback when the iPhone is away from familiar locations. Some account or security changes also have a delay. Apple says the feature must be enabled before a phone is lost or stolen; it is not a substitute for marking a missing phone as lost.
This is an account-and-device safeguard, not a promise that every third-party app will protect every open document. Keep a strong device passcode, enable Stolen Device Protection, install iOS updates, and lock the screen before handing a phone to someone or setting it down.
A second concern is where the backup lives. “Stored on my phone” and “backed up securely” are not the same thing. An offline vault can reduce exposure to cloud account breaches, but if the phone is damaged, the app is removed, or the vault data is lost, there may be no second copy. A cloud vault can help with recovery, but it makes account access and recovery settings part of the security plan.
iPhone options compared: built-in tools and file-vault apps
These are different approaches, not a “best app” ranking. The right one depends on whether your priority is convenience, local-only storage, sharing, or recovery across devices.
Apple Files and the iPhone passcode
Files is a reasonable starting point for ordinary documents you want to keep on your device or organize in iCloud Drive. iOS’s Data Protection system provides a device-level security layer, but Files is not a separate password-protected vault for every folder. Someone using an already-unlocked phone may have a different level of access than someone holding a powered-off or locked device.
If you use iCloud, check which protection mode is enabled. Apple says standard iCloud protection encrypts data in transit and at rest, with Apple holding keys for many categories to support account recovery. Advanced Data Protection is an optional setting that makes the majority of iCloud data—including iCloud Drive and backups—end-to-end encrypted. With it, Apple cannot recover that protected data for you; you need a recovery contact, recovery key, or another supported recovery method.
Locked Apple Notes for notes and supported attachments
For a short private note, Apple Notes has a built-in lock. Apple’s security documentation says locked notes use end-to-end encryption, and documents AES-GCM encryption with a key derived from the user’s passphrase. It also lists which attachment types are supported; not every type of file can be placed in an encrypted note. Use it for content that fits a note, not as a general-purpose folder for every document.
Proton Drive for encrypted cloud access
Proton Drive is a cloud-storage option whose published security model describes end-to-end encryption for file contents and names. Its App Store listing describes access across devices and encrypted storage. That model is useful when you need files beyond one phone, but account security and data recovery matter: Proton explains that after a password reset, encrypted Drive data may require a previous password or recovery phrase/file to regain access. Set up and protect recovery options before you need them.
Cryptomator for an encrypted vault in storage you choose
Cryptomator is designed to create encrypted vaults that can sit in supported cloud storage or local storage. Its documentation describes encryption for file contents and names, and documents an iOS workflow through Apple’s Files app. This approach offers more choice about where the vault is stored, but requires more setup: you need to keep track of the vault password, select a supported storage provider, and understand how the vault is unlocked and backed up.
Cryptomator’s iOS documentation also explains that vaults can stay unlocked for different durations and that certain convenience settings use the iOS Keychain. Read those settings and lock the vault when appropriate, especially on a shared device. Check the current app documentation for supported providers and any workflow limitations.
iKEPT for a local, offline file vault
iKEPT is our app, and it belongs in this comparison as one local-vault option—not as a universal recommendation. Its current App Store description says it stores files offline on the device, encrypts file data before saving it in AsyncStorage, and offers separate access modes, including a secured mode and hidden/decoy features. The listing also describes automatic logout. These details describe the developer’s stated design; this article is not an independent code review or security audit.
There are important limits to what a store listing can prove. In the listing reviewed for this guide, the encryption algorithm, key-derivation method, key-storage design, and a public third-party security audit are not specified. Apple also labels the App Privacy answers as developer-provided and not verified by Apple. That does not prove a flaw, but it means readers should not treat phrases such as “industry-standard” or “uncrackable” as a substitute for technical documentation or independent review.
There is also a recovery tradeoff. iKEPT’s listing warns users to back up files before updating and says deleting the app removes its files. Its version history describes a Mac recovery option for Standard Mode with “no encryption applied.” Treat any recovered or exported copy as an ordinary unencrypted file unless you verify otherwise, and protect it again before moving it elsewhere. Do not keep the only copy of an important document in a local vault.
Hidden or decoy modes may help with privacy in some everyday situations, but they do not prove the encrypted data format is strong, prevent every form of device access, or replace backups. The app’s listing also describes a permanent-delete feature; treat any such feature as destructive and make a separate, tested backup before relying on it.
A four-step method to protect sensitive files on iPhone
- Secure the phone first. Use a strong passcode, keep iOS current, enable Stolen Device Protection, and lock the screen when you are not using it. These steps strengthen the device baseline; they do not replace app-level file protection.
- Choose local storage or sync deliberately. Local-only storage can reduce cloud exposure but raises the risk of losing the only copy. Cloud sync improves access and recovery, but account security, provider controls, and recovery settings become part of your plan.
- Verify what “protected” means. Look for documentation about encryption before files are saved, algorithms and key handling, temporary copies, and backups. A Face ID prompt, hidden folder, or generic “military-grade” label does not establish those details.
- Set a lock and recovery routine. Use an app’s auto-lock option if it has one, avoid unnecessary copies in shared folders, and keep a separate backup you can restore. Test the backup with a non-sensitive file before relying on it.
If the file is a sensitive ID, legal record, or medical document, keep the minimum copies you need. Avoid leaving scans in a general photo library or a shared downloads folder. If you need to share one, verify the recipient and the destination before sending. For ZIP files, our iPhone archive guide also explains why uploading a private archive to an unfamiliar online extractor is a poor shortcut.
Which option fits which need?
- Simple access on one iPhone: use the device passcode and Files for everyday items; use Locked Notes for supported note content.
- Apple devices with stronger iCloud privacy: consider Advanced Data Protection only after setting up and safely storing an account-recovery method.
- Encrypted cloud sync and sharing: compare services such as Proton Drive, and secure the account and recovery credentials as carefully as the files.
- A vault stored with a provider you choose: consider Cryptomator if you are comfortable managing a vault password, supported storage, and lock settings.
- Local offline storage: iKEPT is one option to evaluate. Read the limitations above, confirm the current app details, and keep a separate tested backup.
No app can make every threat disappear. A useful setup is one you understand, can recover from, and can keep updated. For a broader guide to iPhone file handling, see how to unzip files on iPhone safely.