ETER Support Center

Getting Started with ETER 4

Discovering a new app on your device should not be stressful. The must-read guide for all the newcomers to PGP and encryption.

Discovering a new app on your device should not be stressful. The must-read guide for all the newcomers to PGP and encryption.

First of all, I would like to thank you for choosing ETER as your new PGP application. I highly appreciate the amount of trust you are putting into it and will no doubt do my best to meet your expectations.

What is ETER?

ETER (End-to-End Retransmission) is a PGP Suite made specifically for iOS. It utilizes all of the available security measures, such as iOS Keychain, iOS Data Protection, and the Secure Enclave on the devices with enabled biometry, to ensure the unprecedented security of your data. Moreover, one of ETER's most prominent features is the given Oath of Silence - the app never accesses the Internet, so you can be sure about the integrity of your keys. You can easily verify that claim by going to iOS Settings and clicking on ETER in the last section: you will see no Cellular Data switch, the very flag that indicates an app has connected to the Internet at least once.

Part 1. I Have Never Used PGP Before.

To exchange PGP encrypted messages, you will need to have a key pair (only you have the private key) and public keys of your recipient(s). You can generate your first key pair by going to KEYRING->(+).

ETER will present you several text fields that you can modify or leave blank. To successfully generate a key you only need to enter Key Name (only used in ETER) and Key Username (available to everyone who has your public key). If your device does not support biometry, you will also have to create a password - it will not be saved. If your device supports biometry, you may choose not to create a password. In that case, the password will still be created for you, but you will not have to enter it each time* you need to decrypt or sign a message - you will only need to authenticate with your fingerprint & face**.

After you click Generate Key, it will take some time (up to 2 minutes depending on the key strength and the device) to create a key. Once done, you will see your newly generated key in the My Keys table. The same generation procedure should be done on the other's person device.

Now, when the keys are ready, it is time to exchange public keys. That can easily be achieved by swiping right the corresponding key entry and clicking Backup->Retrieve Public Key. You will then have two options to share the public key: through the standard sharing menu or through QR exchange.

  1. Sharing Menu:
    1. Click Open In.
    2. Send the file by using any available method. It is recommended to use AirDrop as it does not leave any traces on 3rd-party mail servers, iCloud etc.
    3. ETER will open automatically on the other device. All you need to do now is to confirm import by clicking Import. If you want, you can change the name of the key that is being imported by clicking on the bold header.
  2. QR Exchange:
    1. Click Share with QR
    2. Go to KEYRING->(+)->QR Import on the other device.
    3. Allow access to Camera, if prompted.
    4. Scan the first QR code. Once a green ribbon in the status bar appears, you can swipe to the next code. If scanned successfully, a circle in the top will become blue. Number of circles corresponds with the number of QR images you need to scan.
    5. Once done scanning, you will need to confirm import by clicking Import. If you want, you can change the name of the key that is being imported by clicking on the bold header.

By now, you should have two keys in My Keys table. The bottom entry with purple key on the right is your key pair and the top entry without the purple key is your recipient's public key.

Part 2. I Already Have A Key Pair.

Currently, there are two ways to import a single key pair into ETER - through text and through a file, binary or ASCII-encoded. The latter is the most convenient import method. It is recommended to use AirDrop as it does not leave any traces on 3rd-party mail servers, iCloud etc.; nevertheless, you can still use any other means of sharing.

If AirDrop presents you with a software choice, you should choose ETER; you should choose Copy to ETER, not PGP Encrypt when using the sharing menu. After that, you will need to confirm import by clicking Import. If you want, you can change the name of the key that is being imported by clicking on the bold header.

If you would like to import a batch of public or private keys, you will need to use Smart Importer (SI) located in ETER Settings. Once you open it, ETER will look for incoming keys both in iTunes File Sharing directory and standard app inbox (files from AirDrop and other apps go there). SI supports importing keys from multiple files, but please note that duplicates of the keys already in the keychain will be grayed out and will not be imported. You can also exclude a key from the import session by swiping left and clicking Delete. Once every key you want is shown, click Import to finalize the process.

Part 3. General Use

To compose your first text-only encrypted message click on the large Encrypt & Sign button. Select (+)->Formatted Text to add a Text Component to your message. Click on the orange rectangle and type the message you would like to encrypt in the Text Editor. You can also add Date & Time of Creation and Location from the attachments menu without turning Export File switch on, thus being able to produce an ETER V3 Link instead of a file. If your recipient does not have ETER, you should change the export type to Standard PGP Armored Message in Message Builder Settings: Edit->(gear icon)->Export Content.

You can easily add a photo from your library or a contact from your Address Book by using available attachments in (+) menu. Please note that if you choose to add anything besides Text, Time and Location, you will not be able to use ETER Links, as you message will stop being text-only. Only standard PGP format, binary or ASCII, will be available for Export and Export in File will be enabled until you remove (swipe left the rectangle) non-text-based attachments.

To finish message building, choose your recipient(s) in the Recipients menu. If you would like to be able to decrypt that message later, you should also choose your own key pair. Choose your key pair in the Signer menu if you would like the recipient to know that this message has come specifically from you (your public key must be present on his or her device). You can now create a template to easily reapply the same selections later. Click on Encrypt or Encrypt & Sign (you will have to authenticate your key) to process your text-based message.

In case of success, you will see a sharing menu:

  1. If Export in File switch is off (it is on by default), the best option is to use iMessage for correspondence as it is the only app that condenses universal links and makes them more visually appealing. You can also use the Copy option to later paste the link in any text area.
  2. If Export in File switch is on, you can use any available means of sharing such as Apple Mail, WhatsApp, Telegram etc. However, you will not be able to use the Copy option.

Your recipient (and you, if you have also chosen your key pair as a recipient) now has several ways to decrypt the encrypted message.

  1. Export in File switch was off
    1. Via Link (if you have chosen ETER V3 or V2 link Export Type), just click on the link.
    2. Via ETER (if you have chosen armored PGP message):
      1. Long press on the encrypted armored text until a tooltip with options appears. Choose Select All and then click on Copy.
      2. Open ETER and navigate to Decrypt & Verify. The message will be pasted automatically. Alternatively, if your device supports 3D touch, you can use the convenient Decrypt Message shortcut.
      3. Click Decrypt.
    3. Via PGP Decrypt Extension (very convenient, if you have chosen armored PGP message):
      1. Long press on the same text until a tooltip with options appears. Choose Select All and then click on Share.
      2. In the second row you should see PGP Decrypt entry - click on it. If you do not see it, you may have to swipe all the way left, click on More and manually enable (must be done only once) ETER's extensions.
    4. Authenticate with your fingerprint/face** or enter the key's password to proceed. In case of success, you should see the decrypted message. By clicking on the first row you can see all of the intended recipients. If your device does not have a public key of one of the recipients, 0x[16 hex digits] (not present) will be shown in the alert instead of its username and email.
  2. Export in File switch was on (gets enabled automatically if attachments contain elements other than Text, Time and Location)
    1. Click on the file.
    2. If the sharing menu is shown, choose Copy to ETER.
    3. If the QuickLook preview with a list of recipients is shown, click on Decrypt.

*You may choose to save the password in memory for the duration of your app session i.e. until ETER is manually closed or unloaded by iOS after a period of inactivity.

**The security of Face ID is arguable. It is advised to set your own password and not permanently store it in ETER for key pairs used to exchange information of utmost importance on devices with Face ID.

I hope this article has been helpful! If you have any suggestions or concerns, please do not hesitate to reach me at [email protected] Your feedback is always welcome!

last updated October 24th, 2018 by Admin