I’ve tried numerous means of securing data on a tablet, but none are quite as interesting and possibly secure as BioWallet Signature. The free biometric authentication tool allows for the locking down of documents within the application, and even the encryption of other folders using your written signature. The encryption used in BioWallet Signature is military grade AES 256 bits, so you know it’s secure; in fact, anything encrypted within the application can only be decrypted using your signature. Plus, the app’s signature recognition is outstanding.


  • Dashboard: Access all documents and features from one simple interface
  • File manager: Built-in file manager allows you to encrypt any folder on your SD card
  • Search: Search only your sensitive information
  • Encryption resistant to brute-force and dictionary cracking


As with any Android application, installation is simple. Open the Android Market application, search for “biowallet” (no quotes), and then tap BioWallet Signature. When the app page is open, tap Install and then tap Accept & Download.

After the installation is complete, you will find an icon on the home screen for BioWallet Signature. Tap the icon and get ready to walk through the setup process.


When you first run the application, you will be presented with the setup wizard (Figure A).
Figure A

This is the welcome page for the setup. Tap Next to continue.

The first screen that requires interaction is shown in Figure B. Enter your User Name, First Name, and Last Name, and then tap Next.
Figure B

The keyboard you see is not a part of BioWallet.

The next step in the process is to register a biometric identity. You can set up a signature and a password. As you would expect, setting up the password is simple. To set up a signature, tap the Signature button to start the Training Mode (Figure C), which is where you can practice your signature. Once you’re comfortable with what you draw, tap Next and you will be ready to enroll your signature. You must successfully re-draw your signature six times in order to enroll the signature. Once you fulfill that requirement, you’re ready to use the tool.
Figure C

Draw your signature here to train the software to recognize your signature.


Think about BioWallet Signature this way: You must successfully draw your signature in order to get into the application to see any data it contains. Once your signature authenticates, you are logged in and can see anything. By default, BioWallet Signature is set up so that once you are logged in, you remain logged in. It’s not until you manually log out that your data is safe from prying eyes. We’ll configure that in a moment.

Once you’re in the application, you can create a new piece of data by tapping Add Record from the Main window. When you tap that button, a list of data types will appear for you to create (Figure D).
Figure D

When entering credit card information, the application recognizes whether the card number is valid.

You can also encrypt folders on the SD card. In order to truly encrypt the file, you want to move it to the private zone. Follow these steps:

  1. From the main window, tap Encrypt.
  2. Navigate to the file you want to encrypt.
  3. Tap the file and then select Move File To Private Zone.
  4. Go back to the Main window.
  5. Tap Explorer.
  6. View the moved file by long-pressing the file name and selecting View.

You now have a file taken from your SD card and hidden away within the BioWallet Signature folder structure. Only people who can authenticate your signature can view the files.

Logging out

It is crucial to log out of BioWallet Signature when you’re finished using it. To do this, tap the Menu button (while in the application) and tap Logout. If you don’t log out, the application will remain logged in and anyone can get to your data.  You should configure BioWallet Signature to log out when your tablet locks; this will prevent data theft if you forget to log out. To do this, follow these steps:

  1. From within BioWallet Signature, tap the Menu button.
  2. Tap Settings.
  3. Tap Security.
  4. Tap the entry for Logout When Locked.
  5. Tap the Back button.
  6. Tap the Back button a second time.

BioWallet Signature is now set up to log out when your tablet locks.

I’ve tested this application to see how far out of the range the signature can be, and it takes a fairly precise  drawing of the signature. If you find it’s not precise enough, you can change the signature security level; the higher the percentage, the more exact the signature has to be. Follow these steps to change the signature security level:

  1. From within the application, tap the Menu button.
  2. Tap Settings.
  3. Tap Security.
  4. Tap Signature Security Level.
  5. When the slider opens, slide the percentage (Figure E) to where you want it.
  6. Tap Test.
  7. Draw signature (you will be informed whether you pass or fail).
  8. Once you pass, click OK to save the setting.

Figure E

You can’t OK the setting until you pass the test.


The BioWallet Signature application is quite good at securing data that should not be seen by prying eyes. The encryption is strong and, unless someone knows how to preciously draw your signature, only you will have access to your data.