Before you can secure an Android app, you must create a keystore for the APK you want to secure. For the Android platform, a keystore is a database of security certificates, created with the keytool utility.
The keytool utility is a standard Java tool used in the Android APK signing process. You can learn more about the keytool utility here:
Example of creating a keystore
Here's a sample command line that creates a keystore called mykeystore.keystore:
keytool -genkey -keyalg RSA -keysize 2048 -validity 10000 -keypass mocanamap \ -keystore mykeystore.keystore -storepass mocanamap -alias mocanadev \ -dname "CN=Acme Console, OU=Eng, O=Acme, L=San Francisco, \ ST=CA, C=US, UID=com.package.name"
Note: The –keypass and –storepass options must be set to the same value.