A couple of interesting PGP applications are available for Windows Phone, which would be useful if you trust the Windows 10 operating system enough to not to upload your cryptographic keys to Microsoft’s servers. I trust it enough for my secondary, less sensitive, email accounts.
OpenPGP for Windows is used for managing the user’s PGP keys and encrypting/decrypting messages. The companion application, OpenPGP Contacts, is used for fetching and storing the public keys for contacts.
Generating a PGP Key
If you already have a public/private key pair, it can be imported in OpenPGP for Windows. If not, it can be created in this application.
And key parameters:
However, I strongly recommend generating the keys on a physical Linux machine.
Previously I have submitted two public keys to keyserver.ubuntu.com, and have added that server in the OpenPGP Contacts settings, which enabled me to store both keys here.
The application has a basic text editor in which to type messages. Whatever is contained here is converted to ciphertext that’s copied to whichever messaging application.
Pressing the ‘+’ button in the ‘To‘ field will display the public keys stored by OpenPGP Contacts, and the text entered here will be encrypted using that key. The encrypted message can be shared with other messaging applications on the device, to send it as an email or text message.
To decrypt, simply copy and paste from the messaging application to OpenPGP application, and select the private key for the decryption.