Developer: BigCatOs

Current Version: 4.4.1

Last Updated: 13 days ago

Download Size: 12.2 MB - Download


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 and movies from your photo album.
• 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.


Release Notes:

- Website redesign requires conforming documentation updates.


Most Helpful Reviews

Version 3.1.1
Review by BradPA

Really useful tool, Security-conscious developer - Krypton is a great little app for keeping your secrets in a convenient place. Developer keeps adding nice features and extras with each version. I use this Mac app and the companion IOS app to keep personal and financial information, instead of a piece of paper in my wallet like my parents would have had to do. It’s great living in the iPhone era!

Found helpful by 4 out of 4 people