android: encrypt ready-made sqlite database then use it

I wrote my sqlite database then i imported to my application, I used this ,and it works fine.

after that I recognized that my database is unencrypted, so with any root phone can access it.

so i suggested this way:

1- encrypt my database with key then

2- return it to my application then

3- use encryption key in my code to decrypt database then

4- I use proguard to encrypt my code(because my code has the encryption key).

does this way is correct?

yes, how to do it?

no, what I must to do?

I read about sqlcipher, but I think this technique to encrypt database from creation.