Signing Android Application with own Signature/Signing Your App Manually

Signing Android Application with own Signature/Signing Your App Manually:

It's not required to have Android SDK to resign your application. You can sign your application (.apk file) with your own signature from command line tools using standard tools and JDK. Just follow below steps to sign your app using Command Prompt

1. Generate a private key using Keytool. Ex:

Use the below command to generate Keystore:

Command:     keytool -genkey -v -keystore default.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

This prompts you for passwords for the keystore and key, and to provide the Distinguished Name fields for your key. It then generates the keystore as a file called my-release-key.keystore. The keystore contains a single key, valid for 10000 days. The alias is a name that you will use later when signing your app

2. Compile your app in release mode to obtain an unsigned APK
3. Sign your app with your private key using jarsigner:

Command:   jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore

Type this command in Java installed path i.e.., Ex: C:\Program Files\Java\jdk1.7.0_51\bin\ - - Command - -

This example prompts you for passwords for the keystore and key. It then modifies the APK in-place to sign it. Note that you can sign an APK multiple times with different keys

4. Verify that your APK is signed. For example:

Command:  jarsigner -verbose –keystore “dubug.keystore” zippedAPp.apk androiddebugkey

5. Align the final APK package using zipalign

Command:  zipalign -v 4 your_project_name-unaligned.apk your_project_name.apk

ZIPALIGN ensures that all uncompressed data starts with a particular byte alignment relative to the start of the file, which reduces the amount of RAM consumed by an app

For more details Refer to following link: http://developer.android.com/tools/publishing/app-signing.html