EphPub Mobile (EphPubDroid)

1. Install EphPubDroid

To install this application, you should allow installation of applications from unknow sources. This option can be found at Settings>Applications> Unknow Sources. Then go through the following steps:

  1. Download Python For Android (PY4A) .apk
  2. Download PyyCrypto .egg file
  3. Install PY4A and open the application
  4. Click on “Import Module” button and then choose “pycrypto-2.3-py2.7-linux-armv.egg”. The application automatically installs this library
  5. Download EphPubDroid .apk
  6. Install and open the application.


  • Access to the Internet (preferably through WiFi)
  • Python For Android (PY4A): you need to download this package manually from the developer’s page on Google Code: Download .apk here
  • Pycrypto 2.3: you need to download this package manually from the developer’s page on Google Code: Download .egg here

2. How to work with EphPubDroid?

When EphPubDroid is loaded for the first time, it will ask you to choose a personal password and type it two times (for confirmation and validation reasons). Through next sessions, at the start up, the application will always ask you for you personal password.

  • Main Page:
    The main (first) page in EphPubDroid application is a black empty interface with a title called “EphPubDroid”. To start working with the application you should click on the menu button on your phone. A context menu will pop up containing 7 sub-menus including: Compose, Retrieve, File Encryption, File Decryption,Manage Accounts, Preferences, Help, Quit.

    1. Manage Accounts:
      By clicking on this sub-menu, a page is loaded which gives you two options: 1) Add a new account 2) Edit existing accounts. If you want to add a new email account in which you receive EphPub messages then you should click on the option (1). Choosing option (1), the application will provide you with a form. You should fill in this form with your accounts details such as email address, user name, password and host’s information. Currently you can add email accounts which you can connect to the mail server through the IMAP protocol. If you want to edit the information about or delete an existing account, then you should choose option (2). By clicking on the option (2), a list of existing accounts will be shown together with a check-box next to each account. you can click on a check-box to choose an account and then click on the menu button on your phone to choose an action which you want to perform on that account (edit/delete). If you click on the edit menu, then the same form as “add a new account” is loaded with the contrast that this time the form is already filled in with the selected account’s details. Otherwise, if you click on delete sub-menu, then the account will be removed from the list forever.
    2. Compose:
      In Compose page you are provided with a text-area to type in your message. Under the text-area there are a drop-down menu, which you can use to specify the life-time of your encrypted message, and a button, by clicking which the encryption process is started and the current page will be close. By the time the encryption process is finished, the compose page will be loaded again where the original text is succeeded with the encrypted one. If you click on the “send” button, then a list will pop up, asking you to choose a program by which you want to send the encrypted message (e.g. Gmail, Messaging, etc.).
    3. Retrieve:
      Using this menu you can decrypt your EphPub messages that are located in your mailboxes (the accounts that you have already added) or copied from e.g. SMSes, etc. Therefore, by clicking on this menu you will be given a list of options: 1) MailBoxes and 2) Solid retrieval. By clicking on the option (1) the application connects to the predefined mail servers and searches for ephpub messages received in the last three days. Then the application shows a list of decryptable messages’ subjects separated by each account’s name. The user can click on each subject to get the decrypted version of the message. By clicking on the option (2), a text-area will be shown in which the user can paste an ephpub message for further decryption.
    4. Preferences:
      This menu gives the user the access to customize application’s settings:

      • En/Disable the auto-syn mailboxes option: if this option is checked the application will search for newly unseened received emails in accounts at predefined intervals. when this option is checked, a drop-down menu will be enabled that the user can use to change the time interval between each synchronization. Currently the option are including: 10 mins, 30 mins and 1 hour.
      • Setting a default TTL
      • Setting a default encryption key size

    5. Quit:
      Exits the application.
    6. Help:
      Loads the manual to work with the application..

3. Caveat

The EphPub extension is a prototype implementation. Please use at your own risk.

  • This application has been tested over Nexus and Samsung Galaxy S II devices on which Android 2.3.3 was running.
  • As this application requires the Internet connection to function fully. Therefore we tested this application in two cases: 1) WiFi was enabled 2) WiFi was disable, 3G was enabled. The tests demonstrated that the success rates is lower under the latter condition. So it is recommended to use the application when the WiFi connection is available.
  • Due to the deficiencies in Facebook API, it is not possible to post an ephpub message on the user’s wall.
  • we have tested to send an ephpub message using the following applications:
    1. Gmail
    2. Android’s default Mail Client
    3. Android’s default Messaging App
    4. Twitter: using this application, the user should notice that message to be encrypted should be very short!