iPGMail 4+

iPGMail is an app that implements the OpenPGP standard (RFC 4880, RFC 6637) and allows the user to create and manage both public and private (RSA, DSA, ECDSA, EDDSA, ECDH) PGP keys and send and receive PGP encrypted messages.

PGP Keys and Messages can be passed to iPGMail several ways:
* From the iOS Mail.app - The iOS mail application will pass PGP attachments to iPGMail directly, eliminating the need to do an awkward copy-and-paste. NOTE: PGP messages that are part of the main body of an email will still have to be copy-and-pasted, only properly tagged attachments can be passed automatically.

* Directly from the system clipboard. Copy-and-paste the PGP message text from any file, webpage, or message, and it can be imported and decrypted by the app.

* iTunes File Sharing - Connect your device to a computer and open up iTunes, in the "Apps" section, you can scroll down and select iPGMail under the File Sharing section and transfer files to and from the app to your computer. Make sure device is unlocked before transferring files!

* AirDrop - Transfer key files from your Mac OS/X system (10.10 or later) to your iPhone/iPad (iOS 7+) using AirDrop feature.

* DropBox - You can link iPGMail to a dropbox account and transfer files to and from your dropbox file space. This means you can encrypt and protect your dropbox files or share files with others through your existing dropbox Public interface.

* Keybase.IO - You can import public keys from http://keybase.io by using the "+" button on the public key listing and then searching for users registered in keybase.io.

iPGMail now allows you to easily reply to encrypted text-based messages and includes the original text with "> " prefixed to the lines. This allows for more email like conversational exchanges, all with strong OpenPGP cryptographic protection.

iPGMail supports PGP key generation (RSA) directly in the app and stores them securely using the iOS keychain for the application. Using your own private PGP keys, you can encrypt and/or digitally sign any messages. Optionally, your public key can be attached to any message you send from the app so that the recipient can then import it into their own keychain, either on the phone or on any computer with PGP support.

iPGMail will import your private keys so you can reuse your existing PGP identity and keys on your iPhone or iPad. Both public and private keys can be imported through the interfaces listed above.

iPGMail allows the user to search public SKS PGP keyservers to find registered public keys for other people with whom the user can then send email that is digitally signed and/or encrypted encoded in OpenPGP ASCII Armor.

This app is ideal for securing your files or for sending secure email messages to specific parties without worrying about it being viewed by anyone other than the designated recipient.

The OpenPGP standard is described here:
http://en.wikipedia.org/wiki/Pretty_Good_Privacy