KryptEY

Keyboard for secure E2EE communication through signal protocol in any messenger
AppID:com.amnesica.kryptey
Author:amnesica
License:GPL-3.0-only
Donation:
InRepoSince:2023-05-22
LastRepoUpdate:2023-05-22
LastAppUpdate:2023-05-21
LastVersion:0.1.5
Categories:Security, System
APK source:Github
Google Play:Check if it's there
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Communicate securely and independent, regardless of the legal situation or whether messengers use E2EE. No server needed. #ChatKontrolleStoppen


Why KryptEY?

Breaking of end-to-end encryption (E2EE) by laws such as the planned EU chat control is an ongoing issue. Content in messengers that use E2EE, such as Whatsapp or Signal, could thus be monitored by third parties. E2EE is often, but not always, standard in messengers. There are proven methods for E2EE such as PGP. However, these methods are sometimes cumbersomely integrated and require a lot of effort to use.

KryptEY is an Android keyboard that implements the Signal protocol. The keyboard works messenger-independently and both the X3DH Key Agreement Protocol and the Double Ratchet Algorithm work without a server, thus it enables a highly independent use of the protocol.


Features

Based upon the Simple Keyboard KryptEY adds a view above the Keyboard for the E2EE functionality.

See this document for further information on how KryptEY is working.


Security

The existing security properties for the Signal Protocol are also valid for the keyboard.


Limitations

The keyboard was designed as a POC and only allows 1-to-1 conversations. However, the application can also be used in a group chat to a limited extent. Here, a message can be directed to a specific chat partner and not to all people. Other participants of the group chat cannot decrypt the message.

Text messages in Telegram are getting copied as HTML and not as plain text. When decoding the message with the fairytale mode the copied message is compromised and can't be read properly. Therefore, it can't be decoded at all. However, the raw mode works properly. When using KryptEY with Telegram we recommend the raw mode.

Some messengers like Threema only allows up to 3500 bytes per message. Therefore, different character input limitations apply. To stay under the 3500 bytes limit, only 500 characters are allowed for raw and fairytale mode. For convenience these limitation applies for all messengers.


Demo

For a demonstration on how KryptEY is used see this link.

WhatsNew:

* Initial release

Hint: This app is available in both, F-Droid Main and IzzyOnDroid repos. For details on this, please see here.
Download Source Issues ChangeLog
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While you can download the APKs here directly, you should preferably use an F-Droid client so the app stays up-to-date on your device. Some clients have this repo enabled by default, e.g. Neo Store or, of course, the IzzyOnDroid client by Sunil. With others (like the official client) you'll have to add this repo manually (see the hint on top of the package list for how to do that).

Packages

Version 0.1.5 (2023-05-22)

Android Versions:
  • Target: 13.0
  • MinVer: 8.0
  • ABIs: arm64-v8a, armeabi-v7a, x86, x86_64
Signing Blocks help icon
App Configuration & Special Access help icon
Permissions: help icon
Malware-Check:Passed help icon
3 Libraries detected: help icon

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