Protecting your personal and confidential information since 2009, Krypton is the first, simplest and most reliable App on the iOS Store to strongly encrypt entire documents and folders. Now also available on the macOS App Store. Your stuff is secure from prying eyes no matter where you are in the world.

Metaphorically, Krypton keeps your encrypted items in a special vault, with each item contained in their own deposit box; to gain access to an encrypted item the vault must be open and the passcode key must be used to unlock the deposit box before you can discern the plaintext contents inside. In iOS the vault may be open or closed, while on macOS the vault opens upon Log In.

Because the unit of encryption is an entire document or folder, Krypton is not a password manager in the traditional sense, although you can maintain a document of all your passwords that you encrypt between uses. Krypton can encrypt any type of document, including but not limited to:

• Pictures from your photo album.
• Movies from your camera roll.
• Email messages from your mailbox.
• Songs, PDFs, movies, Zip files, word processing documents, text files, images, program source code or any other object that you can download over the network or from your personal web server.
• Anything on the iOS pasteboard.
• Any document other Apps are willing to Share, such as Pages, Numbers and Keynote.
• iCloud Drive and Dropbox files for easy cloud synchronization.

Krypton uses strong encryption on each item:

• AES with 256-bit keys, CBC and PKCS7.
• All keys are generated using PBKDF2, SHA-512, random salts and random rounds.
• Every vault item has its own random master key and random IV, used to encrypt the plaintext.
• The master key is itself encrypted.
• The encrypted plaintext and encrypted master key are authenticated with a MAC (Encrypt-Then-MAC).

This has several ramifications:

• If your passcode is strong enough to withstand a brute force attack, no one is going to see your stuff.
• If you forget your passcode, no one can recover your stuff for you! But only that one document is lost, not your entire collection of items.
• Your stuff is secure even if your iDevice or Mac is stolen, or iCloud Drive or Dropbox account is compromised.

Visit to learn more.

What’s New

Version 6.9

- Update for iOS 12.1.4.
- Documentation now supports BigCatOs Appearances.

Ratings and Reviews

5.0 out of 5
2 Ratings

2 Ratings

navamske ,


The UI isn't the best and the proprietary "Krypton terminology" is a bit challenging, but the app gets the job done. I especially like what I regard as two levels of encryption -- first you have to know the combination to get into the "vault," then once you're in you need the file-specific password to view an item. And I like the ability to shred an item after you've viewed it, thereby ensuring (I assume) that it doesn't stay resident in memory in its unencrypted state.

ijaxman ,

Effective but cumbersome

The app does encrypt text and photos but is very cumbersome to use. I would recommend it for highly sensitive information but there are some attributes that make it a pain for items that one would like to access frequently.

Pluses: it does encrypt. Once things are encrypted the UI is good.

Minuses: encrypts what's on the clipboard/pasteboard. The risk here is that whatever is in the pasteboard could sync with the cloud and defeat the whole purpose of this app. One could always do the encryption in airplane mode to avoid that possibility.

Another issue is that photos don't scale to fit the screen. I opened a random picture from Photos, copied it then returned to the app to encrypt it. That worked successfully. Upon decrypting the photo it appeared in full-size on the screen which meant I had to move around the screen to see all of the picture, it didn't shrink to fit the screen.

But perhaps the biggest downside is that the app will not let you encrypt a file without a hideously long (granted, secure) password. I wanted to put my goals for this year in the app. That's not exactly a state secret but it is personal information. However, it's not worth it to me to have to enter a monster password for this purpose.

In my opinion this is a great app for encrypting information that could cause you harm if revealed but pretty cumbersome for frequent use.

Rserkes ,


This is a great app that does exactly what it says it'll do. I can encrypt sensitive documents before loading them onto my iPad and then decrypt them as needed. If my iPad is stolen I have the security of knowing that prying eyes won't see those encrypted documents.

I would have given it five stars if there had been a WiFi transfer feature. Having to tether my iPad to my iMac via a USB cable to transfer the encrypted documents is cumbersome. For those folks with a MobileMe account why not upload the encrypted documents to a private folder and then download from MobileMe directly into Krypton?


Technology Man IR
94.7 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
Copyright (©) 2009 - 2019 Stephen O. Lidie, All rights reserved.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like