Kryptos

Installing the new version is recommended. Kryptos 2.4 is not compatible with older versions.

New features:

• Brazilian Portuguese.
• The language switch key is now a globe key (you can also switch keyboards by holding the globe key).
• The iOS app icon is now native.
• Libraries updated to the latest versions.
• Links, email addresses, and phone numbers in decrypted text can now be copied.
• Vibration mode setting.
• Key text size setting.
• Key press enlargement setting.
• The cursor in the keyboard input field can be moved by dragging with your finger.
• Comma key instead of the emoji key; emoji are now available by holding the comma key.

• Option to disable automatic capitalization.
• Settings are now stored in an encrypted file.
• Third-party keyboards no longer suggest words in Kryptos fields.
• Passwords in "Password" and "Photo" modes must now be at least 6 characters long.
• Code entry is locked after 5 incorrect attempts.
• The keyboard and on-screen decryption are locked 5 minutes after leaving the app.
• When using "Trap Password", the keyboard is hidden, on-screen decryption is disabled, and access to the camera and microphone is blocked.
• Other changes.

Fixes:

• Key flickering when moving the cursor by holding the space bar.
• Disappearing messages were deleted with a delay.
• The lock could be bypassed by setting the clock back.
• The locked keyboard displayed profiles and contacts and allowed switching profiles.
• The "Storage unavailable" screen could erase everything with a single tap without confirmation.
• On-screen decryption displayed text on the locked device.
• Text from disappearing messages remained in the cache.
• The keyboard draft remained visible after locking.
• The keyboard could remember words from encrypted messages.
• File names revealed whether codes had been set.
• Windows and menus were not protected against being overlaid by other apps.
• The app could freeze when handling a large message.
• The mask key is no longer derived from public fingerprints.
• Other fixes.

Downloads:

The APK is built in the F-Droid buildserver container and signed with the same key as before, so it installs over an existing copy. The IPA is unsigned.

Kryptos:

Kryptos is an iPhone and Android app that encrypts conversations inside any messenger.

You type the message straight into WhatsApp, Telegram or an SMS, tap the padlock on the Kryptos keyboard, and the field holds ciphertext instead of your text. On the other end it works the other way round: on Android Kryptos decrypts the text on screen without leaving the messenger, on iPhone it shows the text above the keyboard once the ciphertext is copied. The messenger, the carrier and anyone who intercepts the message on the way see a run of characters they cannot read.

The app is the same on both systems and uses one format, so it does not matter which phone your contact carries.